Abstract
Background
Although the elderly population is increasing rapidly, little information is available regarding how the risk of postoperative mortality and morbidity increases when combined with age and comorbidity burden in patients undergoing musculoskeletal tumor surgery.
Questions/purposes
We evaluated the effect of age and comorbidity burden on the (1) postoperative complication rate and (2) in-hospital mortality rate after musculoskeletal tumor surgery.
Methods
We identified 5716 patients undergoing musculoskeletal tumor surgery during 2007 to 2012 using a Japanese national inpatient database. Logistic regression analyses were performed to examine the relationships of various factors with the rates of mortality and morbidity.
Results
The postoperative complication rate (6.7%) was associated with male sex (p = 0.033), age 80 years or older (p = 0.001), tumor located in the lower extremity (p = 0.001) or trunk (p = 0.019), Charlson Comorbidity Index of 4 or greater (p < 0.001), blood transfusion (p < 0.001), and duration of anesthesia of 240 minutes or longer (p < 0.001). The in-hospital mortality (0.8%) was related to the Charlson Comorbidity Index of 4 or greater (p < 0.001), blood transfusion (p < 0.001), and high hospital volume (p = 0.016). The morbidity (21.6%; OR, 3.29; p < 0.001) and mortality (4.1%; OR, 5.95; p < 0.001) in patients 80 years or older with a Charlson Comorbidity Index of 4 or greater was increased three and six times, respectively, compared with patients 64 years or younger with no comorbidity.
Conclusions
We found that age and comorbidity burden together greatly increased the risk of morbidity and mortality. Our study showed quantitative evidence that will assist physicians in assessing perioperative risk accurately and provide a more informative explanation to elderly patients undergoing musculoskeletal tumor surgery.
Level of Evidence
Level IV, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.
Introduction
In patients with musculoskeletal sarcomas, complete resection with a negative surgical margin is a potentially curative treatment option. However, surgical treatment frequently demands an aggressive approach to achieve this objective. The proportion of the elderly population is rapidly increasing owing to demographic changes, and this trend is particularly evident in Japan where 23% of the population are 65 years or older [6, 9, 10, 12]. Consequently, the number of elderly patients with musculoskeletal sarcomas who are treated surgically also is increasing [9]. Surgeons and medical oncologists may be hesitant to treat elderly patients in a comparably intensive manner as that used for treatment of younger patients because the elderly usually have decreased performance status and several comorbidities and the natural history of disease may reduce enthusiasm for aggressive surgical intervention.
Studies of the surgical outcomes in elderly patients with various malignancies have been reported [2, 3, 11, 17, 18]. However, little information is available regarding the therapeutic outcomes in elderly patients with musculoskeletal sarcomas, and some studies have relatively small cohorts [1, 2, 4, 9, 15]. These studies mainly highlighted the long-term outcome with an endpoint of tumor-related death, local recurrence, or metastasis [1, 2, 4, 9, 15], and little information is available regarding the effect of advanced age or comorbidity on the short-term outcomes. Perioperative mortality and morbidity have not been well documented. Presumably, some musculoskeletal oncologists have had patients with several postoperative complications or patients who died after surgery and they may recognize the population at greater risk of these complications or death. However, to our knowledge, quantitative evidence to determine the effect of age and comorbidity burden on the risk of having postoperative complications or death after musculoskeletal tumor surgery has been lacking. More understanding of the effect of each factor would allow surgeons to better evaluate the perioperative risk for elderly patients with musculoskeletal sarcomas.
We therefore evaluated the effect of age and comorbidity burden on the (1) postoperative complication rate and (2) in-hospital mortality rate after musculoskeletal tumor surgery.
Patients and Methods
Data Source
The Diagnosis Procedure Combination database is a national administrative claims and discharge abstract data on acute-care inpatients in Japan, the details of which have been described [6, 8, 13, 14]. Data were collected during 6 months (from July 1 to December 31) until 2010 and throughout the year from 2011. The numbers of admissions in the database were 2.7, 2.8, 2.8, 3.3, and 7.0 million in 2007, 2008, 2009, 2010, and 2011, respectively, representing approximately 50% of all inpatient admissions to secondary- and tertiary-care hospitals in Japan.
The database includes the following data for each patient: location of hospital; age and sex; diagnoses and comorbidities at admission and complications after admission recorded with text data in the Japanese language and the ICD-10 codes; procedures coded with Japanese original codes; drugs and devices used; length of hospital stay; and discharge status. Complications that occur after admission are clearly differentiated from comorbidities present at admission.
Because of the anonymous nature of the data, informed consent for this study was waived. Study approval was obtained from the Institutional Review Board of The University of Tokyo.
Data Extraction
Two authors (KO and HY) retrospectively identified the records of all patients in the Diagnosis Procedure Combination database who underwent musculoskeletal tumor surgery (bone tumor resection [Japanese procedure code, K053]; soft tissue tumor resection [K031]; and amputation [K084]) for a primary malignant musculoskeletal tumor (malignant bone tumor [ICD-10 codes, C40.x, C41.x]; and primary malignant soft tissue tumor [C47.x, C48.0, C49.x]) during 2007 to 2012. Of the approximately 20 million inpatients whose data were collected in the database during this period, we identified 5716 eligible patients at 409 hospitals who underwent musculoskeletal tumor surgery (Table 1). For each patient, we extracted the following data: sex, age, main diagnosis, tumor location, type of surgery, presence or absence of blood transfusion, duration of anesthesia, postoperative length of stay, and the following comorbidities (ICD-10 codes) that may affect the rates of postoperative complications or in-hospital mortality: diabetes mellitus (E10.x-E14.x), chronic lung disease (I27.8, I27.9, J40.x-J47.x, J60.x-J67.x, J68.4, J70.1, J70.3), cardiac disease (I25.2, I09.9, I11.0, I13.0, I13.2, I20.x, I21.x, I22.x, I25.5, I42.0, I42.5-I42.9, I43.x, I50.x, P29.0), cerebrovascular disease (G45.x, G46.x, H34.0, I60.x-I69.x), chronic renal failure (N18.x), and liver disease (I85.0, I85.9, I86.4, I98.2, K70.4, K71.1, K72.1, K72.9, K76.5, K76.6, K76.7). Based on the protocol of Quan et al. [16], each ICD-10 code of a comorbidity was converted to a score, and the sum of the scores was used to calculate the patient’s Charlson Comorbidity Index [5]. The Charlson Comorbidity Index assigns points for different types of comorbidities; for example, 1 point each for diabetes and heart disease, 2 points for a malignant tumor, 3 points for liver disease, and 6 points for metastatic malignancy. A Charlson Comorbidity Index of 2 in this study indicates a patient has no preoperative comorbidities except for musculoskeletal tumor.
Table 1.
Characteristics of the study population according to surgical procedures
| Variable | Overall (n = 5716) | Soft tissue tumor resection (n = 4534) | Bone tumor resection (n = 896) | Amputation (n = 286) | p value |
|---|---|---|---|---|---|
| Age (years)* | 58 (20) | 61 (18) | 46 (23) | 56 (24) | |
| Age group (number of patients) | < 0.001 | ||||
| ≤ 64 years | 3183 (56%) | 2373 (52%) | 643 (72%) | 167 (58%) | |
| 65–79 years | 1845 (32%) | 1551 (34%) | 218 (24%) | 76 (27%) | |
| ≥ 80 years | 688 (12%) | 610 (14%) | 35 (4%) | 43 (15%) | |
| Sex (number of patients) | 0.222 | ||||
| Male | 3129 (55%) | 2463 (54%) | 496 (55%) | 170 (59%) | |
| Female | 2587 (45%) | 2071 (46%) | 400 (45%) | 116 (41%) | |
| Tumor site (number of patients) | < 0.001 | ||||
| Upper extremity | 839 (15%) | 712 (16%) | 65 (7%) | 62 (22%) | |
| Lower extremity | 2692 (47%) | 2256 (50%) | 292 (33%) | 144 (50%) | |
| Trunk | 1715 (30%) | 1141 (25%) | 519 (58%) | 55 (19%) | |
| Unknown | 470 (8%) | 425 (9%) | 20 (2%) | 25 (9%) | |
| Charlson Comorbidity Index (number of patients) | < 0.001 | ||||
| 2 | 4206 (74%) | 3345 (74%) | 676 (75%) | 185 (65%) | |
| 3 | 863 (15%) | 710 (16%) | 113 (13%) | 40 (14%) | |
| ≥ 4 | 647 (11%) | 479 (10%) | 107 (12%) | 61 (21%) | |
| Hospital volume (number of patients) | < 0.001 | ||||
| ≤ 13 cases | 1741 (31%) | 1476 (33%) | 186 (21%) | 79 (28%) | |
| 14–28 cases | 2062 (36%) | 1596 (35%) | 350 (39%) | 116 (40%) | |
| ≥ 29 cases | 1913 (33%) | 1462 (32%) | 360 (40%) | 91 (32%) | |
| Blood transfusion (number of patients) | < 0.001 | ||||
| No | 4702 (82%) | 4058 (89%) | 438 (49%) | 206 (72%) | |
| Yes | 1014 (18%) | 476 (11%) | 458 (51%) | 80 (28%) | |
| Anesthesia time (minutes)† | 216 (142–345) | 195 (135–307) | 379 (251–567) | 204 (157–278) | < 0.001 |
| Anesthesia time group (number of patients) | < 0.001 | ||||
| ≤ 120 minutes | 932 (17%) | 862 (19%) | 44 (5%) | 26 (9%) | |
| 121–240 minutes | 2261 (40%) | 1951 (44%) | 159 (18%) | 151 (54%) | |
| > 240 minutes | 2417 (43%) | 1646 (37%) | 666 (77%) | 105 (37%) | |
| Postoperative length of stay (days)† | 19 (11–35) | 17 (11–29) | 35 (19–66) | 29 (17–56) | < 0.001 |
* Values are expressed as mean, with SD in parentheses; †values are expressed as median, with interquartile range in parentheses.
Diagnoses (ICD-10 codes) were categorized in two groups: primary malignant bone tumor (C40.x, C41.x) or primary malignant soft tissue tumor (C47.x, C48.0, C49.x), and tumor location was categorized in three subgroups: upper extremity, lower extremity, or trunk. The type of surgery was categorized in three subgroups: bone tumor resection, soft tissue tumor resection, or amputation. The Diagnosis Procedure Combination data do not include information regarding duration of surgery, but the period of anesthesia generally reflects this. The duration of anesthesia was categorized as less than 120 minutes, 120 to 240 minutes, or more than 240 minutes. The hospital volumes for all musculoskeletal surgery were determined using the unique identifier for each hospital and categorized by patient tertiles into low (< 13 cases/year), medium (14–28 cases/year), or high volume (> 28 cases/year). Patients were divided in tertiles according to hospital volume (number of musculoskeletal surgeries per year) so that the number of patients in each group was almost equal: low, 13 or fewer/year; medium, 14 to 28/year; or high, 29 or more/year.
Endpoints
The primary endpoints were (1) in-hospital mortality rate and (2) postoperative rate of complications (ICD-10 codes), including surgical site infection (T813), sepsis (A40.x, A41.x), pulmonary embolism (I26.x), cardiac events (I20.x, I21.x, I50.x), respiratory complications (J10.x-J18.x, J95.2, J96.0), cerebrovascular events (I60.x-I64.x), and acute renal failure (N17.x).
Statistical Analyses
We performed univariate comparisons of proportions using the chi-square test and comparisons of means using ANOVA. Logistic regression analyses were performed to examine the relationships of each factor with the rates of postoperative complications and in-hospital mortality. Differences were considered statistically significant with p values less than 0.1 in univariate analyses and less than 0.05 in multivariate analyses.
Results
The overall rate of postoperative complications was 6.7% (381 of 5716): 6.3% in the group 64 years or younger, 6.1% in the group 65 to 79 years old, and 9.9% in the group 80 years or older (Table 2). Univariate analyses showed higher postoperative complication rates for males than for females (p = 0.009); for patients 80 years or older (p = 0.001); for patients with tumor location in the lower extremity (p < 0.001) or trunk (p = 0.001) rather than in the upper extremity; patients with a Charlson Comorbidity Index of 3 (p < 0.001) or with a Charlson Comorbidity Index of 4 or greater (p < 0.001); patients who underwent bone tumor resection than for patients who underwent soft tissue tumor resection (p = 0.049), patients who received blood transfusion (p < 0.001); patients with duration of anesthesia of 120 to 240 minutes (p = 0.077) or greater than 240 minutes (p < 0.001) rather than less than 120 minutes; and for patients treated in medium-volume hospitals rather than low-volume hospitals (p = 0.048) (Table 3). Multivariate analyses showed associations between postoperative complication rates and female sex (odds ratio [OR], 0.79; 95% CI, 0.63–0.98; p = 0.033), age of 80 years or older (OR, 1.68; 95% CI, 1.23–2.30; p = 0.001), tumor location in the lower extremity (OR, 1.96; 95% CI, 1.33–2.91; p = 0.001) or trunk (OR, 1.65; 95% CI, 1.08–2.50; p = 0.019), Charlson Comorbidity Index of 3 (OR, 1.93; 95% CI, 1.47–2.55; p < 0.001), or Charlson Comorbidity Index of 4 or more (OR, 2.85; 95% CI, 2.17–3.74; p < 0.001), blood transfusion (OR, 1.79; 95% CI, 1.37–2.34; p < 0.001), and duration of anesthesia greater than 240 minutes (OR, 2.66; 95% CI, 1.78–3.98; p < 0.001) (Table 3).
Table 2.
Postoperative complications and in-hospital mortality for each surgical procedure
| Variable | Number of patients | p value | |||
|---|---|---|---|---|---|
| Overall (n = 5716) | Soft tissue tumor resection (n = 4534) | Bone tumor resection (n = 896) | Amputation (n = 286) | ||
| In-hospital death | 45 (0.8%) | 30 (0.7%) | 9 (1.0%) | 6 (2.1%) | 0.021 |
| ≤ 64 years | 23 (0.7%) | 12 (0.5%) | 6 (0.9%) | 5 (3.0%) | 0.001 |
| 65–79 years | 11 (0.6%) | 8 (0.5%) | 3 (1.4%) | 0 (0.0%) | |
| ≥ 80 years | 11 (1.6%) | 10 (1.6%) | 0 (0.0%) | 1 (2.3%) | |
| Postoperative complications | |||||
| Surgical site infection | 242 (4.2%) | 195 (4.3%) | 39 (4.4%) | 8 (2.8%) | 0.464 |
| Cardiac events | 61 (1.1%) | 45 (1.0%) | 12 (1.3%) | 4 (1.4%) | 0.558 |
| Respiratory complications | 36 (0.6%) | 26 (0.6%) | 7 (0.8%) | 3 (1.0%) | 0.506 |
| Sepsis | 26 (0.5%) | 13 (0.3%) | 9 (1.0%) | 4 (1.4%) | 0.001 |
| Pulmonary embolism | 17 (0.3%) | 11 (0.2%) | 5 (0.6%) | 1 (0.3%) | 0.281 |
| Acute renal failure | 7 (0.1%) | 4 (0.1%) | 2 (0.2%) | 1 (0.3%) | 0.303 |
| Cerebrovascular events | 5 (0.1%) | 5 (0.1%) | 0 (0.0%) | 0 (0.0%) | 0.521 |
| At least one complication | 381 (6.7%) | 288 (6.4%) | 73 (8.1%) | 20 (7.0%) | 0.140 |
| ≤ 64 years | 201 (6.3%) | 130 (5.5%) | 56 (8.7%) | 15 (9.0%) | 0.004 |
| 65–79 years | 112 (6.1%) | 95 (6.1%) | 14 (6.4%) | 3 (3.8%) | |
| ≥ 80 years | 68 (9.9%) | 63 (10.3%) | 3 (8.6%) | 2 (4.7%) | |
Table 3.
Univariate and multivariate logistic regression analyses for postoperative complications
| Variable | Number of patients | Number of patients with complications (%) | Univariate analysis | Multivariate analysis | ||
|---|---|---|---|---|---|---|
| Odds ratio (95% CI) | p value | Odds ratio (95% CI) | p value | |||
| Total | 5716 | 381 (6.7%) | ||||
| Sex | ||||||
| Male | 3129 (55%) | 233 (7.4%) | Reference | Reference | ||
| Female | 2587 (45%) | 148 (5.7%) | 0.75 (0.61–0.93) | 0.009 | 0.79 (0.63–0.98) | 0.033 |
| Age | ||||||
| ≤ 64 years | 3183 (56%) | 201 (6.3%) | Reference | Reference | ||
| 65–79 years | 1845 (32%) | 112 (6.1%) | 0.96 (0.76–1.22) | 0.730 | 0.91 (0.71–1.17) | 0.482 |
| ≥ 80 years | 688 (12%) | 68 (9.9%) | 1.63 (0.22–2.17) | 0.001 | 1.68 (1.23–2.30) | 0.001 |
| Tumor location | ||||||
| Upper extremity | 846 (15%) | 32 (3.8%) | Reference | Reference | ||
| Lower extremity | 2698 (47%) | 207 (7.7%) | 2.11 (1.45–3.09) | < 0.001 | 1.96 (1.33–2.91) | 0.001 |
| Trunk | 1718 (30%) | 124 (7.2%) | 1.98 (1.33–2.95) | 0.001 | 1.65 (1.08–2.50) | 0.019 |
| Data not provided | 454 (8%) | 18 (4.0%) | 1.05 (0.58–1.89) | 0.871 | 0.85 (0.45–1.59) | 0.611 |
| Charlson Comorbidity Index | ||||||
| 2 | 4206 (74%) | 202 (4.8%) | Reference | Reference | ||
| 3 | 863 (15%) | 87 (10.1%) | 2.22 (1.71–2.89) | < 0.001 | 1.93 (1.47–2.55) | < 0.001 |
| ≥ 4 | 647 (11%) | 92 (14.2%) | 3.29 (2.53–4.27) | < 0.001 | 2.85 (2.17–3.74) | < 0.001 |
| Type of surgery | ||||||
| Soft tissue tumor resection | 4534 (79%) | 288 (6.4%) | Reference | Reference | ||
| Bone tumor resection | 896 (16%) | 73 (8.1%) | 1.31 (1.00–1.71) | 0.049 | 0.80 (0.58–1.11) | 0.180 |
| Amputation | 286 (5%) | 20 (7.0%) | 1.11 (0.69–1.77) | 0.667 | 0.91 (0.56–1.48) | 0.696 |
| Blood transfusion | ||||||
| Yes | 1014 (18%) | 126 (12.4%) | 2.47 (1.98–3.10) | < 0.001 | 1.79 (1.37–2.34) | < 0.001 |
| Anesthesia time | ||||||
| < 120 minutes | 932 (17%) | 31 (3.3%) | Reference | Reference | ||
| 120–240 minutes | 2261 (40%) | 107 (4.7%) | 1.44 (0.96–2.17) | 0.077 | 1.40 (0.93–2.12) | 0.107 |
| > 240 minutes | 2417 (43%) | 234 (9.7%) | 3.12 (2.13–4.57) | < 0.001 | 2.66 (1.78–3.98) | < 0.001 |
| Hospital volume | ||||||
| Low | 1741 (31%) | 131 (7.5%) | Reference | Reference | ||
| Medium | 2062 (36%) | 122 (5.9%) | 0.773 (0.60–0.99) | 0.048 | 0.71 (0.54–0.93) | 0.108 |
| High | 1913 (33%) | 128 (6.7%) | 0.88 (0.68–1.14) | 0.327 | 0.89 (0.68–1.16) | 0.391 |
The overall in-hospital mortality rate was 0.8% (45 of 5716): 0.7% in the group 64 years or younger, 0.6% in the group 65 to 79 years, and 1.6% in the group 80 years or older. Univariate analyses showed higher in-hospital mortality rates in patients 80 years or older (p = 0.030), patients with a Charlson Comorbidity Index of 3 (p = 0.038) or with a Charlson Comorbidity Index of 4 or higher (p < 0.001), patients who underwent amputation than patients who underwent soft tissue tumor resection (p = 0.010), patients who received blood transfusion (p < 0.001), and patients treated in high-volume hospitals than low-volume hospitals (p = 0.009) (Table 4). Multivariate analyses showed associations between in-hospital mortality rates and Charlson Comorbidity Index of 4 or greater (OR, 4.06; 95% CI, 2.05–8.03; p < 0.001), blood transfusion (OR, 10.95; 95% CI, 5.59–21.44; p < 0.001), and high-volume hospital (OR, 0.34; 95% CI, 0.14–0.82; p = 0.016) (Table 4). Because elderly patients frequently have several coexisting comorbidities, preoperative risk should be evaluated with consideration of age and comorbidity, and therefore, we performed additional analyses of postoperative complications (Fig. 1A) and in-hospital mortality (Fig. 1B) focusing on age and Charlson Comorbidity Index. The morbidity and mortality in patients 80 years or older with a Charlson Comorbidity Index of 4 was approximately three (OR, 3.29; 95% CI, 2.53–4.27; p < 0.001) and six times (OR, 5.95; 95% CI, 3.07–11.05; p < 0.001), respectively, as frequent as for patients 64 years or younger with no preoperative comorbidity.
Table 4.
Univariate and multivariate logistic regression analyses for in-hospital mortality
| Variable | Number of patients | Number of patients with in-hospital death (%) | Univariate analysis | Multivariate analysis | ||
|---|---|---|---|---|---|---|
| Odds ratio (95% CI) | p value | Odds ratio (95% CI) | p value | |||
| Total | 5716 | 45 (0.8%) | ||||
| Sex | ||||||
| Male | 3129 (55%) | 27 (0.9%) | Reference | Reference | ||
| Female | 2587 (45%) | 18 (0.7%) | 0.81 (0.44–1.47) | 0.478 | 0.74 (0.40–1.37) | 0.335 |
| Age | ||||||
| ≤ 64 years | 3183 (56%) | 23 (0.7%) | Reference | Reference | ||
| 65–79 years | 1845 (32%) | 11 (0.6%) | 0.82 (0.40–1.63) | 0.599 | 0.72 (0.34–1.50) | 0.376 |
| ≥ 80 years | 688 (12%) | 11 (1.6%) | 2.23 (1.08–4.60) | 0.030 | 1.71 (0.78–3.73) | 0.178 |
| Tumor location | ||||||
| Upper extremity | 846 (15%) | 4 (0.5%) | Reference | |||
| Lower extremity | 2698 (47%) | 19 (0.7%) | 1.49 (0.51–4.40) | 0.467 | ||
| Trunk | 1718 (30%) | 19 (1.1%) | 2.35 (0.80–6.94) | 0.121 | ||
| Data not provided | 454 (8%) | 3 (0.7%) | 1.40 (0.31–6.28) | 0.660 | ||
| Charlson Comorbidity Index | ||||||
| 2 | 4206 (74%) | 19 (0.5%) | Reference | Reference | ||
| 3 | 863 (15%) | 9 (1.0%) | 2.32 (1.05–5.15) | 0.038 | 1.86 (0.82–4.23) | 0.137 |
| ≥ 4 | 647 (11%) | 17 (2.6%) | 5.95 (3.07–11.50) | < 0.001 | 4.06 (2.05–8.03) | < 0.001 |
| Type of surgery | ||||||
| Soft tissue tumor resection | 4534 (79%) | 30 (0.7%) | Reference | Reference | ||
| Bone tumor resection | 896 (16%) | 9 (1.0%) | 2.52 (0.72–3.22) | 0.270 | 0.65 (0.28–1.47) | 0.295 |
| Amputation | 286 (5%) | 6 (2.1%) | 3.22 (1.33–7.79) | 0.010 | 1.57 (0.62–3.97) | 0.343 |
| Blood transfusion | ||||||
| Yes | 1014 (18%) | 31 (3.1%) | 10.56 (5.60–19.92) | < 0.001 | 10.95 (5.59–21.44) | < 0.001 |
| Anesthesia time | ||||||
| < 120 minutes | 932 (17%) | 6 (0.6%) | Reference | |||
| 120–240 minutes | 2261 (40%) | 12 (0.5%) | 0.82 (0.31–2.20) | 0.699 | ||
| > 240 minutes | 2417 (43%) | 24 (1.0%) | 1.55 (0.63–3.80) | 0.340 | ||
| Hospital volume | ||||||
| Low | 1741 (31%) | 20 (1.1%) | Reference | Reference | ||
| Medium | 2062 (36%) | 18 (0.9%) | 0.76 (0.40–1.44) | 0.396 | 0.74 (0.38–1.45) | 0.384 |
| High | 1913 (33%) | 7 (0.4%) | 0.32 (0.13–0.75) | 0.009 | 0.34 (0.14–0.82) | 0.016 |
Fig. 1A–B.
The (A) postoperative complications and (B) in-hospital mortality stratified by age and Charlson Comorbidity Index are shown. CCI = Charlson Comorbidity Index.
Discussion
Although nearly 50% of patients with soft tissue sarcoma are older than 65 years, it was reported that elderly patients with musculoskeletal sarcoma did not receive definitive treatment until the 1990s [7]. Farshadpour et al. [7] analyzed 40 patients with soft tissue sarcomas who received no definitive treatment and reported that 23% of these patients who were 65 years or older had treatment withheld for patient-related reasons, such as patient refusal, comorbidity, or poor general condition. With demographic changes and the rapid increase in the number of elderly patients with musculoskeletal sarcomas, more elderly patients are likely to require surgical intervention. However, it usually is difficult to treat elderly patients in an intensive manner comparable to that for younger patients because of their decreased performance status and comorbidities. Musculoskeletal tumor surgery is challenging and potentially is associated with high complication rates. In addition, little information regarding the effect of advanced age or comorbidity burden on rates of mortality and postoperative complications make it difficult to judge whether surgical intervention should be performed in such populations. We therefore evaluated the effect of age and comorbidity burden on the (1) postoperative complication rate and (2) in-hospital mortality rate after musculoskeletal tumor surgery. Our study showed that advanced age and comorbidity burden together greatly increased the risk of morbidity and mortality.
Our study has several limitations. First, the use of an administrative claims database could have led to underestimation or overestimation of comorbidities or postoperative complications because of incomplete reporting. Second, the participation rate of small hospitals in the Diagnosis Procedure Combination database was relatively low, which may have resulted in a sample selection bias. However, there are few patients with musculoskeletal sarcomas treated in small non-Diagnosis Procedure Combination hospitals because patients with sarcomas in Japan usually are treated in academic hospitals or cancer treatment centers that participate in the Diagnosis Procedure Combination system. Third, we were unable to determine complications and deaths after discharge or transfer to another hospital, which may have resulted in underestimation of these outcomes. However, most patients with postoperative complications or in-hospital death would be included in our analysis, as the median postoperative hospital stay was 19 days, and the majority of such early postoperative events occur during that period. Fourth, we were not able to identify several important clinical parameters that may have affected the rates of postoperative complications and mortality, including histologic diagnosis, clinical stage of the tumor, severity of preoperative comorbidities, adjuvant chemotherapy and radiotherapy, and details of the surgery. Fifth, we were not able determine the decision process for treatment because we extracted only the data of patients with musculoskeletal sarcoma treated surgically. Therefore, the indication for surgery in elderly patients with numerous comorbidities may have been different among hospitals, which may have resulted in selection bias. Finally, it is possible that individual patients may have been counted more than once in the database if they initially received inappropriate surgical treatment at a local hospital and then underwent surgery in a specialized hospital. However, such cases are rare in Japan because there are a limited number of hospitals specializing in musculoskeletal oncology, and patients usually are referred to a specialized hospital if a musculoskeletal sarcoma is suspected.
Despite these limitations, we believe that our results are epidemiologically important, as they show the incidence of postoperative complications and in-hospital death after musculoskeletal tumor surgery in the Japanese population. The population from the Diagnosis Procedure Combination database is representative of the population in Japan and includes the majority of patients undergoing musculoskeletal tumor surgery in Japan. The data included approximately 50% of all the hospital admissions in Japan during 2011. According to data from the nationwide bone and soft tissue tumor registry in Japan, more than 80% of patients with primary musculoskeletal tumors underwent surgery at university hospitals or cancer treatment centers contributing to the Diagnosis Procedure Combination system because of the rarity of the disease and the specialized surgical procedures required.
Several investigators have reported the clinical outcomes of elderly patients with musculoskeletal sarcomas along with the demographic changes (aging) and the development of perioperative management [1, 2, 4, 9, 15]. However, these reports mainly highlighted the long-term outcome such as metastasis, local recurrence, or tumor-related death, and little information is available regarding short-term surgical outcomes such as morbidity and mortality [2, 4, 9]. The perioperative mortality and morbidity was 0.9% to 2.2% and 31% to 38%, respectively [2, 4, 9]. The mortality rate for our study patients was comparable to rates reported previously and the morbidity in our study patients was less than reported for patients in the previous studies. However, direct comparison with existing data is difficult since these were based on small cohorts of patients with different definitions of aged. Although there have been no previous reports regarding how advanced age and comorbidity burden increase the risk of postoperative complications and in-hospital mortality, our results showed that the comorbidity burden as measured by the Charlson Comorbidity Index was strongly associated with postoperative complications and in-hospital mortality. Advanced age (80 years or older) was associated with an approximately twofold increase in the risk of postoperative complications, whereas no association was noted with in-hospital mortality. The morbidity and mortality in patients 80 years or older with a Charlson Comorbidity Index of 4 was approximately three and six times, respectively, as frequent as in patients 64 years or younger with no preoperative comorbidity (Fig. 1). Quantitative data regarding the effect of age and comorbidity burden on postoperative morbidity and mortality after musculoskeletal tumor surgery have been lacking, and our results will enable physicians to assess perioperative risk more accurately and inform their patients of their overall risk for surgery. In addition, because the Charlson Comorbidity Index can predict 1-year mortality from preexisting comorbidity, a comparison between predicted tumor mortality and death from preexisting comorbidity also may be beneficial for treatment decision-making.
We believe that our findings provide critical information regarding the factors associated with poorer outcomes in patients undergoing surgical treatment for musculoskeletal sarcoma. The study indicated that age and comorbidity burden together greatly increased the risk of morbidity and mortality. A greater understanding of each factor’s contribution to postoperative outcomes would allow surgeons to better evaluate perioperative risk.
Footnotes
The institutions of two of the authors (HY and KF) have received, during the study period, funding from a Grant-in-Aid for Research on Policy Planning and Evaluation from the Ministry of Health, Labour and Welfare, Japan (Grant Number: H22-Policy-031), and by the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST program) from the Council for Science and Technology Policy, Japan (Number 0301002001001). Each author certifies that he or she, or a member of his or her immediate family, has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research ® editors and board members are on file with the publication and can be viewed on request.
Each author certifies that his or her institution has approved the reporting of this report and that all investigations were conducted in conformity with ethical principles of research.
References
- 1.Al-Refaie WB, Habermann EB, Dudeja V, Vickers SM, Tuttle TM, Jensen EH, Virnig BA. Extremity soft tissue sarcoma care in the elderly: insights into the generalizability of NCI Cancer Trials. Ann Surg Oncol. 2010;17:1732–1738. doi: 10.1245/s10434-010-1034-z. [DOI] [PubMed] [Google Scholar]
- 2.Boden RA, Clark MA, Neuhaus SJ, A’Hern JR, Thomas JM, Hayes AJ. Surgical management of soft tissue sarcoma in patients over 80 years. Eur J Surg Oncol. 2006;32:1154–1158. doi: 10.1016/j.ejso.2006.05.016. [DOI] [PubMed] [Google Scholar]
- 3.Brozzetti S, Mazzoni G, Miccini M, Puma F, De Angelis M, Cassini D, Bettelli E, Tocchi A, Cavallaro A. Surgical treatment of pancreatic head carcinoma in elderly patients. Arch Surg. 2006;141:137–142. doi: 10.1001/archsurg.141.2.137. [DOI] [PubMed] [Google Scholar]
- 4.Buchner M, Bernd L, Zahlten-Hinguranage A, Sabo D. Primary malignant tumours of bone and soft tissue in the elderly. Eur J Surg Oncol. 2004;30:877–883. doi: 10.1016/j.ejso.2004.06.013. [DOI] [PubMed] [Google Scholar]
- 5.Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40:373–383. doi: 10.1016/0021-9681(87)90171-8. [DOI] [PubMed] [Google Scholar]
- 6.Chikuda H, Yasunaga H, Horiguchi H, Takeshita K, Sugita S, Taketomi S, Fushimi K, Tanaka S. Impact of age and comorbidity burden on mortality and major complications in older adults undergoing orthopaedic surgery: an analysis using the Japanese diagnosis procedure combination database. BMC Musculoskelet Disord. 2013;14:173. doi: 10.1186/1471-2474-14-173. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Farshadpour F, Schaapveld M, Suurmeijer AJ, Wymenga AN, Otter R, Hoekstra HJ. Soft tissue sarcoma: why not treated? Crit Rev Oncol Hematol. 2005;54:77–83. doi: 10.1016/j.critrevonc.2004.10.006. [DOI] [PubMed] [Google Scholar]
- 8.Kadono Y, Yasunaga H, Horiguchi H, Hashimoto H, Matsuda S, Tanaka S, Nakamura K. Statistics for orthopedic surgery 2006–2007: data from the Japanese Diagnosis Procedure Combination database. J Orthop Sci. 2010;15:162–170. doi: 10.1007/s00776-009-1448-2. [DOI] [PubMed] [Google Scholar]
- 9.Lahat G, Dhuka AR, Lahat S, Lazar AJ, Lewis VO, Lin PP, Feig B, Cormier JN, Hunt KK, Pisters PW, Pollock RE, Lev D. Complete soft tissue sarcoma resection is a viable treatment option for select elderly patients. Ann Surg Oncol. 2009;16:2579–2586. doi: 10.1245/s10434-009-0574-6. [DOI] [PubMed] [Google Scholar]
- 10.Muramatsu N, Akiyama H. Japan: super-aging society preparing for the future. Gerontologist. 2011;51:425–432. doi: 10.1093/geront/gnr067. [DOI] [PubMed] [Google Scholar]
- 11.Muss HB. Cancer in the elderly: a societal perspective from the United States. Clin Oncol (R Coll Radiol). 2009;21:92–98. doi: 10.1016/j.clon.2008.11.008. [DOI] [PubMed] [Google Scholar]
- 12.Nakamura KA. “super-aged” society and the “locomotive syndrome.”. J Orthop Sci. 2008;13:1–2. doi: 10.1007/s00776-007-1202-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Ogura K, Yasunaga H, Horiguchi H, Ohe K, Kawano H. Incidence and risk factors for pulmonary embolism after primary musculoskeletal tumor surgery. Clin Orthop Relat Res. 2013;471:3310–3316. doi: 10.1007/s11999-013-3073-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Ogura K, Yasunaga H, Horiguchi H, Ohe K, Shinoda Y, Tanaka S, Kawano H. Impact of hospital volume on postoperative complications and in-hospital mortality after musculoskeletal tumor surgery: analysis of a national administrative database. J Bone Joint Surg Am. 2013;95:1684–1691. doi: 10.2106/JBJS.L.00913. [DOI] [PubMed] [Google Scholar]
- 15.Osaka S, Sugita H, Osaka E, Yoshida Y, Ryu J. Surgical management of malignant soft tissue tumours in patients aged 65 years or older. J Orthop Surg (Hong Kong). 2003;11:28–33. doi: 10.1177/230949900301100107. [DOI] [PubMed] [Google Scholar]
- 16.Quan H, Sundararajan V, Halfon P, Fong A, Burnand B, Luthi JC, Saunders LD, Beck CA, Feasby TE, Ghali WA. Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data. Med Care. 2005;43:1130–1139. doi: 10.1097/01.mlr.0000182534.19832.83. [DOI] [PubMed] [Google Scholar]
- 17.Staehler M, Haseke N, Stadler T, Bader M, Karl A, Becker A, Stief CG. Renal surgery in the elderly: morbidity in patients aged > 75 years in a contemporary series. BJU Int. 2008;102:684–687. doi: 10.1111/j.1464-410X.2008.07794.x. [DOI] [PubMed] [Google Scholar]
- 18.Tan KY, Kawamura Y, Mizokami K, Sasaki J, Tsujinaka S, Maeda T, Konishi F. Colorectal surgery in octogenarian patients: outcomes and predictors of morbidity. Int J Colorectal Dis. 2009;24:185–189. doi: 10.1007/s00384-008-0615-9. [DOI] [PubMed] [Google Scholar]