Abstract
Purpose
Breast cosmesis and breast pain are among the most reported outcomes in patients undergoing adjuvant breast irradiation. The degree to which such adverse reactions occur can be variable based on different patient-specific characteristics. It has been found that women with a larger body habitus, and larger breasts, tend to have an increased chance of experiencing worse toxicity from treatment. As such, attempts to improve cosmetic and pain outcomes have been a highly explored topic. One such technique, that is studied here, is to explore whether the use of a breast cup during treatment leads to worse breast pain and cosmetic outcomes when compared with those treated without a breast cup. This proves to be an important topic because it is believed that the use of a breast cup would provide a significant dosimetric advantage (ie, breast coverage and organ at risk dosing) during treatment. We now explore this treatment option through the scope of a retrospective analysis of patient-reported outcomes experienced during and after completing postoperative radiation therapy to the breast.
Methods and Materials
A total of 645 patients undergoing adjuvant breast irradiation were evaluated from 2011 to 2019. Of the 645 patients, 79 were treated using a breast cup. The mean heart dose was analyzed and compared between the 2 treatment groups. Additionally, patient-reported outcomes among the entire cohort were collected via survey documentation forms during treatment, at 1 month after the completion of treatment, and at 1 year after the completion of treatment. These results were collected using the Michigan Radiation Oncology Quality Consortium database because each patient was consented to enroll in the Michigan Radiation Oncology Quality Consortium prior to starting treatment. The outcomes of skin changes, lymphedema, and breast pain among the 2 treatment groups were then compared for statistically significant differences via a logistic regression analysis.
Results
Of the 79 patients treated with a breast cup, grade 2 pruritus of the treated breast along with grade 1 alteration in skin texture was reported in 49.4%, 35.4%, and 22.8% while on treatment, at 1 month after the completion of treatment, and at 1 year after treatment, respectively; P-values were nonsignificant at all timepoints when data compared with non-cup-treated patients. With regard to lymphedema, 59.5%, 40.5%, and 10.1% of breast cup patients at the prespecified timepoints reported this sequela; all P-values were nonsignificant except for the 1-month mark (P-value .03). Lastly, breast pain was noted in 36.7%, 15.2%, and 11.4% of breast cup-treated patients while on treatment, at 1 month after the completion of treatment, and at 1 year after treatment, respectively; again, P-values for data analysis at each timepoint were nonsignificant. Other than the patient-reported outcome of lymphedema 1 month after the completion of treatment, no statistical significance was seen in comparing side effects between the 2 treatment arms.
Conclusions
From our patients’ perspective, the use of a breast cup during radiation therapy did not negatively impact breast cosmesis or pain when compared with patients treated without a cup. Furthermore, breast cup use was also found to produce a lower overall mean heart dose in patients with left-sided breast cancer.
Introduction
Breast cancer is the most common noncutaneous malignancy diagnosed in the US female population. Its incidence has continued to increase annually at 0.5% per year, with estimates from the American Cancer Society predicting that this year will yield approximately 285,000 new cases of invasive breast cancer, 50,000 cases of in situ disease, and 43,000 deaths from breast cancer.1 To battle this disease, treatment trends show that radiation therapy (RT) is used in more than 50% of the eligible cases because many women choose to pursue a breast conservation approach in the world today.2 Although choosing such an approach can help avoid the side effect profile associated with undergoing mastectomy, there remains a possibility for a separate subset of treatment-related reactions from radiation. From the patient's perspective, breast irradiation can cause local toxicities such as swelling, pain, and skin texture and color changes.3 These side effects are especially seen in Black patients and other patients with darker skin tones.4
In terms of treatment planning, many cases provide challenges in minimizing the dose to the organs at risk (heart and lungs) while also trying to provide a homogenous dose to the required treatment volume.5 Often, it is the natural anatomic position of the treated breast that is the determining factor in the significance of breast RT sequelae. Breast position appears to be most impacted by the size of the breast along with the degree of associated pendulosity. Larger, defined as a volume of 1200 mL or greater, and more pendulous breasts (Regnault ptosis classification ≥ 2) have been found to have a greater risk of increased heart/lung dose along with challenges in dose homogeneity, in addition to encountering the expected increased breast skin side effects.6,7 Furthermore, left-sided breast radiation, in particular, has historically led to a higher mean heart dose than right-sided cases. This value only increases as breast volume and ptosis increase.
Although breast size does not directly lead to an increased risk of developing breast cancer, there is an association between obesity and breast density.8,9 Women with obesity are also more likely to have pendulous breasts than women within the normal body mass index range. As such, the aforementioned breast RT sequelae are not only more significant in women with obesity with pendulous breasts but also more prevalent. To combat this, there have been many efforts to create different treatment techniques to reduce the treatment risks in this population. Although maneuvers such as deep inspiratory breath-hold (DIBH), prone treatment technique, and intensity modulated RT have worked well for many left-sided breast cancers, it has still not entirely solved the problem for women with larger breasts. These women often experience difficulty lying prone and/or with deep breath-hold requirements. The large size of a breast may also preclude prone treatment if the breast reaches and lies against the treatment table. These patient-specific factors complicate treatment planning and can result in an inability to replicate positioning. In addition, larger breast volume results in a larger treatment field impacting the organs at risk.
To aid the population of patients with larger and more pendulous breasts, attempts to treat patients while they wear their own bras have been tried,10 and the creation and use of a radiation immobilization tool known as a breast cup (Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6) has been employed.5,10 Both have been able to show promising results with regard to comparable skin toxicity, improved breast dose homogeneity, and decreased dose to organs at risk by manipulating the breast to a more anterior versus inferior-lateral position.11
Figure 1.
Bird's-eye view of a left breast cup. The strap is wrapped around the patient's back and attaches to the loop hole on the medial side of the cup.
Figure 2.
Side view of the left breast cup.
Figure 3.
A close-up picture of the lateral side of a breast cup showing the hole that lines up with a patient tattoo for daily placement.
Figure 4.
Second view of the breast cup with the holes that line up to patient tattoos marked with blue circles.
Figure 5.
Left breast cup in use with an approximately 1500 mL size breast at the time of the simulation.
Figure 6.
Lateral view of a pendulous left breast in breast cup.
This data analysis aims to further investigate larger-breasted women who have been treated with the use of a breast cup. The goal is to further validate that the use of a breast cup to aid in delivering RT to women with larger breasts not only provides better treatment planning dosimetry but also that the use of a breast cup does not worsen any of the commonly seen side effects from breast RT; skin changes, swelling/lymphedema, and breast pain. This will be accomplished through the scope of a retrospective analysis of patient-reported outcomes (PROs) experienced during and after completing postoperative RT to the breast.
Materials and Methods
A total of 645 patients undergoing adjuvant breast irradiation were evaluated from 2011 to 2019 during participation in a statewide quality consortium PRO evaluation. Of these 645 patients, 324 (50.2%) patients had left-sided breast cancer, and 321 (49.8%) patients had right-sided breast cancer. Seventy-nine of the 645 patients were treated using a breast cup: 47 left breast patients and 32 right breast patients. At our facility, a breast cup is used for the treatment of any patient with a large pendulous breast that overlies the chest wall when the patient is placed on a breast board (Figs. 1, 2). The breast cup is donned and secured on patients in a sitting position, and then, they are assisted in laying back onto the breast board. Each breast cup has 3 holes on the medial, superior, and lateral sides (Fig. 3). After simulation measurements are taken, a tattoo is placed at each hole to ensure cup placement and setup are replicated (Fig. 4). We take pictures of the breast in the cup to show how it lays (Figs. 5, 6). During treatment, daily kilo-voltage/ mega-voltage films are taken to confirm the setup.
Patient demographics collected during this study included race, age, body mass index, and breast volume were assessed. The majority of patients enrolled were Black/African American (74.4%), with the remaining quarter of patients identifying as either Caucasian or other (Table 1). The mean age of the enrolled candidates was 62.7 years old with the majority of subject's body mass index falling within the obesity range in both arms (Table 1). With regard to breast volume, the overall mean breast volume was measured at 1290 mL. On further breakdown, it was found that the mean breast volume for patients treated with a breast cup was 1780 mL, whereas a mean volume of only 1220 mL was seen in the patient population treated without a breast cup (Table 1). Patients requiring the breast cup were unable to tolerate DIBH and all 79 of them were treated without DIBH. We attribute this additional treatment planning challenge to larger body habitus, obesity, and subsequently decreased physical activity tolerance. Of note, our facility began using a DIBH device (active breath control machine) in 2019 which is where the data for this retrospective analysis ends. Prior to that year, we did not have access to this machine; therefore, the breast cup was our technique to immobilize large pendulous breasts and create reproducible clinical setups.
Table 1.
Patient characteristics
| Overall | With cup | No cup | |
|---|---|---|---|
| (N = 645) | (N = 79) | (N = 566) | |
| Year of RT | |||
| 2011 | 1 (0.2%) | 0 (0%) | 1 (0.2%) |
| 2012 | 73 (11.3%) | 8 (10.1%) | 65 (11.5%) |
| 2013 | 71 (11.0%) | 8 (10.1%) | 63 (11.1%) |
| 2014 | 79 (12.2%) | 9 (11.4%) | 70 (12.4%) |
| 2015 | 77 (11.9%) | 11 (13.9%) | 66 (11.7%) |
| 2016 | 101 (15.7%) | 16 (20.3%) | 85 (15.0%) |
| 2017 | 78 (12.1%) | 9 (11.4%) | 69 (12.2%) |
| 2018 | 71 (11.0%) | 7 (8.9%) | 64 (11.3%) |
| 2019 | 94 (14.6%) | 11 (13.9%) | 83 (14.7%) |
| Race | |||
| Black | 480 (74.4%) | 68 (86.1%) | 412 (72.8%) |
| Other | 56 (8.7%) | 4 (5.1%) | 52 (9.2%) |
| White | 109 (16.9%) | 7 (8.9%) | 102 (18.0%) |
| Age | |||
| Mean (SD) | 62.7 (12.0) | 65.9 (11.5) | 62.2 (12.0) |
| Median (min, max) | 62.3 (20.0, 91.2) | 66.3 (43.1, 89.3) | 61.5 (20.0, 91.2) |
| BMI category | |||
| Missing | 3 (0.5%) | 2 (2.5%) | 1 (0.2%) |
| <25 | 91 (14.1%) | 7 (8.9%) | 84 (14.8%) |
| 25-30 | 165 (25.6%) | 11 (13.9%) | 154 (27.2%) |
| 30-35 | 173 (26.8%) | 26 (32.9%) | 147 (26.0%) |
| 35-40 | 113 (17.5%) | 14 (17.7%) | 99 (17.5%) |
| 40+ | 100 (15.5%) | 19 (24.1%) | 81 (14.3%) |
| Left/right | |||
| Left | 324 (50.2%) | 47 (59.5%) | 277 (48.9%) |
| Right | 321 (49.8%) | 32 (40.5%) | 289 (51.1%) |
| Skin toxicity-related comorbidity | |||
| No | 184 (28.5%) | 8 (10.1%) | 176 (31.1%) |
| Yes | 461 (71.5%) | 71 (89.9%) | 390 (68.9%) |
| ER status | |||
| Negative | 141 (21.9%) | 17 (21.5%) | 124 (21.9%) |
| Positive | 503 (78.0%) | 61 (77.2%) | 442 (78.1%) |
| Missing | 1 (0.2%) | 1 (1.3%) | 0 (0%) |
| Nodes treated as part of plan | |||
| No | 586 (90.9%) | 74 (93.7%) | 512 (90.5%) |
| Yes | 59 (9.1%) | 5 (6.3%) | 54 (9.5%) |
| Surgical margins | |||
| Missing | 5 (0.8%) | 2 (2.5%) | 3 (0.5%) |
| Close/negative | 630 (97.7%) | 77 (97.5%) | 553 (97.7%) |
| Positive | 10 (1.6%) | 0 (0%) | 10 (1.8%) |
| Use of boost | |||
| No | 148 (22.9%) | 20 (25.3%) | 128 (22.6%) |
| Yes | 497 (77.1%) | 59 (74.7%) | 438 (77.4%) |
| Dose/fraction | |||
| >2.5 | 293 (45.4%) | 32 (40.5%) | 261 (46.1%) |
| ≤2.5 | 222 (34.4%) | 31 (39.2%) | 191 (33.7%) |
| Miss | 130 (20.2%) | 16 (20.3%) | 114 (20.1%) |
| Hormone therapy | |||
| No | 180 (27.9%) | 20 (25.3%) | 160 (28.3%) |
| Yes | 465 (72.1%) | 59 (74.7%) | 406 (71.7%) |
| Chemotherapy | |||
| No | 417 (64.7%) | 56 (70.9%) | 361 (63.8%) |
| Yes | 228 (35.3%) | 23 (29.1%) | 205 (36.2%) |
| Use of deep inspiratory breath-hold (DIBH) | |||
| No | 637 (98.8%) | 79 (100%) | 558 (98.6%) |
| Yes | 8 (1.2%) | 0 (0%) | 8 (1.4%) |
| Breast volume (100) | |||
| Mean (SD) | 12.9 (6.53) | 17.8 (7.31) | 12.2 (6.09) |
| Median (min, max) | 12.0 (0.567, 38.4) | 18.2 (0.567, 37.4) | 11.3 (1.63, 38.4) |
| Missing | 113 (17.5%) | 12 (15.2%) | 101 (17.8%) |
| Mean heart dose | |||
| Mean (SD) | 1.5 (1.1) | 1.7 (1.3) | 1.5 (1.1) |
| Median (min, max) | 1.2 (0, 6.4) | 1.4 (0.1, 6.4) | 1.1 (0, 6.4) |
Abbreviations: BMI = body mass index; RT = radiation therapy; ER = estrogen.
Mean heart dose (MHD) and PROs, including breast pain, lymphedema, pruritus, or burning sensation, were collected via survey documentation during treatment. Additional PROs were added to surveys during follow-up, including breast size, shape, texture, elevation, tenderness, sensitivity, and scar tissue. Follow-up assessments were performed at 1 month after the completion of treatment and 1 year after the completion of treatment. These results were collected using the Michigan Radiation Oncology Quality Consortium database because each patient was consented to enroll in the Michigan Radiation Oncology Quality Consortium prior to starting treatment. The outcomes were then compared for statistically significant differences via a logistic regression analysis.
Results
In comparing MHD between patient groups, it was found that MHD was very similar. The average MHD was 1.7 Gy in the breast cup-treated patients and 1.5 Gy in the non-cup-treated patients. Among these 2 groups, both recorded a maximum MHD of 6.4 Gy in a small subset of patients, whereas the minimum recorded was 0 Gy in the non-cup-treated group and 0.1 Gy in the cup-treated group (Table 1).
With regard to PROs, skin toxicity is reviewed first. During treatment, it was found that 49.4% of patients who were treated with a breast cup reported skin changes (manifest as pruritus), while 47.7% of patients treated without a breast cup reported the same finding, P-value .5336. Similar complaints of pruritus were again noted at 1 month following the completion of breast RT in 35.4% of breast cup-treated patients and 28.3% of non-breast cup-treated patients, P-value .4148. Finally, skin changes assessed at 1 year after breast RT showed that 22.8% of patients treated using a breast cup reported changes in skin texture, while the same finding was noted in 28.8% of the patients treated without a cup, P-value .188 (Table 2).
Table 2.
Patient-reported outcomes (PROs)
| Overall | Yes | No | P-value | |
|---|---|---|---|---|
| (N = 645) | (N = 79) | (N = 566) | ||
| PROs during treatment | ||||
| Lymphedema (G1+): swelling of your treated breast | ||||
| Missing | 109 (16.9%) | 7 (8.9%) | 102 (18%) | |
| No | 297 (46%) | 25 (31.6%) | 157 (27.7%) | .8826 |
| Yes | 239 (37.1%) | 47 (59.5%) | 307 (54.2%) | |
| Skin disorder: pruritus (G2+): itching of the skin of your treated breast | ||||
| Missing | 108 (16.7%) | 7 (8.9%) | 101 (17.8%) | |
| No | 228 (35.3%) | 33 (41.8%) | 195 (34.5%) | .5336 |
| Yes | 309 (47.9%) | 39 (49.4%) | 270 (47.7%) | |
| Breast pain (G4+): 0-10 | ||||
| Missing | 108 (16.7%) | 7 (8.9%) | 101 (17.8%) | |
| No | 394 (61.1%) | 43 (54.4%) | 351 (62%) | .3697 |
| Yes | 143 (22.2%) | 29 (36.7%) | 114 (20.1%) | |
| Sting or burning (G2+) | ||||
| Missing | 108 (16.7%) | 7 (8.9%) | 101 (17.8%) | |
| No | 233 (36.1%) | 35 (44.3%) | 198 (35%) | .3367 |
| Yes | 304 (47.1%) | 37 (46.8%) | 267 (47.2%) | |
| Fatigue (G2+) | ||||
| Missing | 482 (74.7%) | 56 (70.9%) | 426 (75.3%) | |
| No | 29 (4.5%) | 3 (3.8%) | 26 (4.6%) | .5206 |
| Yes | 134 (20.8%) | 20 (25.3%) | 114 (20.1%) | |
| PROs at end of treatment | ||||
| Lymphedema (G1+): swelling of your treated breast | ||||
| Missing | 169 (26.2%) | 13 (16.5%) | 156 (27.6%) | |
| No | 282 (43.7%) | 24 (30.4%) | 158 (27.9%) | .7360 |
| Yes | 194 (30.1%) | 42 (53.2%) | 252 (44.5%) | |
| Skin disorder: pruritus (G2+): itching of the skin of your treated breast | ||||
| Missing | 136 (21.1%) | 10 (12.7%) | 126 (22.3%) | |
| No | 241 (37.4%) | 32 (40.5%) | 209 (36.9%) | .8621 |
| Yes | 268 (41.6%) | 37 (46.8%) | 231 (40.8%) | |
| Breast pain (G4+): 0-10 | ||||
| Missing | 118 (18.3%) | 8 (10.1%) | 110 (19.4%) | |
| No | 376 (58.3%) | 51 (64.6%) | 325 (57.4%) | .9228 |
| Yes | 151 (23.4%) | 20 (25.3%) | 131 (23.1%) | |
| Sting or burning (G2+) | ||||
| Missing | 147 (22.8%) | 12 (15.2%) | 135 (23.9%) | |
| No | 255 (39.5%) | 29 (36.7%) | 226 (39.9%) | .1632 |
| Yes | 243 (37.7%) | 38 (48.1%) | 205 (36.2%) | |
| Fatigue (G2+) | ||||
| Missing | 141 (21.9%) | 10 (12.7%) | 131 (23.1%) | |
| No | 173 (26.8%) | 19 (24.1%) | 154 (27.2%) | .2011 |
| Yes | 331 (51.3%) | 50 (63.3%) | 281 (49.6%) | |
| PROs at 1 month | ||||
| Lymphedema (G1+): swelling of your treated breast | ||||
| Missing | 219 (34%) | 21 (26.6%) | 198 (35%) | |
| No | 342 (53%) | 26 (32.9%) | 220 (38.9%) | .0321 |
| Yes | 84 (13%) | 32 (40.5%) | 148 (26.1%) | |
| Skin disorder: pruritus (G2+): itching of the skin of your treated breast | ||||
| Missing | 180 (27.9%) | 17 (21.5%) | 163 (28.8%) | |
| No | 277 (42.9%) | 34 (43%) | 243 (42.9%) | .4148 |
| Yes | 188 (29.1%) | 28 (35.4%) | 160 (28.3%) | |
| Breast pain (G4+): 0-10 | ||||
| Missing | 164 (25.4%) | 15 (19%) | 149 (26.3%) | |
| No | 424 (65.7%) | 52 (65.8%) | 354 (62.5%) | .4546 |
| Yes | 57 (8.8%) | 12 (15.2%) | 63 (11.1%) | |
| Sting or burning (G2+) | ||||
| Missing | 193 (29.9%) | 22 (27.8%) | 171 (30.2%) | |
| No | 338 (52.4%) | 39 (49.4%) | 299 (52.8%) | .2371 |
| Yes | 114 (17.7%) | 18 (22.8%) | 96 (17%) | |
| Difference between treated and untreated breast (0-3) | ||||
| Breast size (G1+) | ||||
| Missing | 187 (29%) | 19 (24.1%) | 168 (29.7%) | |
| No | 83 (12.9%) | 8 (10.1%) | 75 (13.3%) | .3016 |
| Yes | 375 (58.1%) | 52 (65.8%) | 323 (57.1%) | |
| Breast texture (G1+) | ||||
| Missing | 198 (30.7%) | 20 (25.3%) | 178 (31.4%) | |
| No | 158 (24.5%) | 21 (26.6%) | 137 (24.2%) | .9661 |
| Yes | 289 (44.8%) | 38 (48.1%) | 251 (44.3%) | |
| Breast tenderness (G1+) | ||||
| Missing | 189 (29.3%) | 20 (25.3%) | 169 (29.9%) | |
| No | 159 (24.7%) | 23 (29.1%) | 136 (24%) | .4772 |
| Yes | 297 (46%) | 36 (45.6%) | 261 (46.1%) | |
| Breast shape (G1+) | ||||
| Missing | 196 (30.4%) | 20 (25.3%) | 176 (31.1%) | |
| No | 114 (17.7%) | 9 (11.4%) | 105 (18.6%) | .055 |
| Yes | 335 (51.9%) | 50 (63.3%) | 285 (50.4%) | |
| Breast elevation (G1+) | ||||
| Missing | 196 (30.4%) | 20 (25.3%) | 176 (31.1%) | |
| No | 166 (25.7%) | 20 (25.3%) | 146 (25.8%) | .5998 |
| Yes | 283 (43.9%) | 39 (49.4%) | 244 (43.1%) | |
| Scar tissue (G1+) | ||||
| Missing | 202 (31.3%) | 21 (26.6%) | 181 (32%) | |
| No | 113 (17.5%) | 10 (12.7%) | 103 (18.2%) | .1213 |
| Yes | 330 (51.2%) | 48 (60.8%) | 282 (49.8%) | |
| Breast swelling (G1+) | ||||
| Missing | 187 (29%) | 19 (24.1%) | 168 (29.7%) | |
| No | 262 (40.6%) | 28 (35.4%) | 234 (41.3%) | .0768 |
| Yes | 196 (30.4%) | 32 (40.5%) | 164 (29%) | |
| Breast sensitivity (G1+) | ||||
| Missing | 183 (28.4%) | 19 (24.1%) | 164 (29%) | |
| No | 156 (24.2%) | 21 (26.6%) | 135 (23.9%) | .8285 |
| Yes | 306 (47.4%) | 39 (49.4%) | 267 (47.2%) | |
| PROs at 1 y | ||||
| Breast pain (G4+): 0-10 | ||||
| Missing | 311 (48.2%) | 35 (44.3%) | 276 (48.8%) | |
| No | 289 (44.8%) | 35 (44.3%) | 254 (44.9%) | .1455 |
| Yes | 45 (7%) | 9 (11.4%) | 36 (6.4%) | |
| Difference between treated and untreated breast (0-3) | ||||
| Breast size (G1+) | ||||
| Missing | 329 (51%) | 38 (48.1%) | 291 (51.4%) | |
| No | 59 (9.1%) | 4 (5.1%) | 55 (9.7%) | .1164 |
| Yes | 257 (39.8%) | 37 (46.8%) | 220 (38.9%) | |
| Breast texture (G1+) | ||||
| Missing | 329 (51%) | 41 (51.9%) | 288 (50.9%) | |
| No | 135 (20.9%) | 20 (25.3%) | 115 (20.3%) | .188 |
| Yes | 181 (28.1%) | 18 (22.8%) | 163 (28.8%) | |
| Breast tenderness (G1+) | ||||
| Missing | 327 (50.7%) | 38 (48.1%) | 289 (51.1%) | |
| No | 165 (25.6%) | 24 (30.4%) | 141 (24.9%) | .3612 |
| Yes | 153 (23.7%) | 17 (21.5%) | 136 (24%) | |
| Breast shape (G1+) | ||||
| Missing | 328 (50.9%) | 40 (50.6%) | 288 (50.9%) | |
| No | 92 (14.3%) | 8 (10.1%) | 84 (14.8%) | .2112 |
| Yes | 225 (34.9%) | 31 (39.2%) | 194 (34.3%) | |
| Breast elevation (G1+) | ||||
| Missing | 340 (52.7%) | 40 (50.6%) | 300 (53%) | |
| No | 118 (18.3%) | 14 (17.7%) | 104 (18.4%) | .7016 |
| Yes | 187 (29%) | 25 (31.6%) | 162 (28.6%) | |
| Scar tissue (G1+) | ||||
| Missing | 337 (52.2%) | 40 (50.6%) | 297 (52.5%) | |
| No | 93 (14.4%) | 10 (12.7%) | 83 (14.7%) | .5074 |
| Yes | 215 (33.3%) | 29 (36.7%) | 186 (32.9%) | |
| Breast swelling (G1+) | ||||
| Missing | 329 (51%) | 39 (49.4%) | 290 (51.2%) | |
| No | 246 (38.1%) | 32 (40.5%) | 214 (37.8%) | .7258 |
| Yes | 70 (10.9%) | 8 (10.1%) | 62 (11%) | |
| Breast sensitivity (G1+) | ||||
| Missing | 330 (51.2%) | 40 (50.6%) | 290 (51.2%) | |
| No | 162 (25.1%) | 21 (26.6%) | 141 (24.9%) | .7469 |
| Yes | 153 (23.7%) | 18 (22.8%) | 135 (23.9%) |
In evaluating the symptoms of breast swelling, 59.5% of patients treated with a breast cup reported grade 1 lymphedema of the treated breast during RT, while 54.2% of the non-cup patients noted the same finding, P-value .8826. At the 1-month time mark following the completion of radiation, grade 1 lymphedema was again reported in patients treated either with or without a breast cup in 40.5% and 26.1% of patients, respectively, P-value .0321. Finally, breast swelling was evaluated at 1 year following RT. At that time, breast swelling was reported in 10.1% of patients who were treated with the aid of a breast cup versus 11% of those treated without a cup, P-value .7258.
Finally, pain in the treated breast was queried and followed from treatment onset through 1 year after the completion of RT. During treatment, breast pain was documented in 36.7% of the patients treated with a breast cup and 20.1% of the patients treated without a P-value .3697. At 1 month after treatment, complaints of breast pain had decreased to 15.2% and 11.1% within the breast cup and non-cup patient populations, respectively, P-value .4546. Finally, reported outcomes at 1 year after completion of RT yielded the finding of breast pain in 11.4% of breast cup-treated patients and 6.4% of non-cup-treated patients, P-value .1455.
On analysis of all of the PROs noted earlier, only one specific PRO, lymphedema, was found to have a statistically significant outcome at 1 month post-treatment. Otherwise, no statistically significant difference was seen for any PRO pertaining to RT-related side effects at any specified timepoint between the 2 patient groups.
Discussion
The use of breast immobilization devices is not novel. In fact, evidence supporting its practicality has already been established prior to this analysis. Whether it is via the use of a breast cup5 or the patient's own bra,10 breast positioning during RT has been found to be a factor that can significantly impact treatment outcomes. The data presented here support the idea that breast positioning devices provide a significant benefit to patients receiving breast RT. Additionally, it is believed that the results truly validate such a benefit because this analysis includes a more robust patient cohort than any previous study, a greater number of patients analyzed and a larger breadth of ethnically diverse patients. Our study consisted of a total of 79 patients who were treated with a breast cup, where Stewart et al5 and Joseph et al11 had 18 and 16 patients, respectively. Furthermore, our patient group consisted largely of Black/African American patients which does not appear to be noted in other works. We think that this allows our results to be more generalizable across more patient subsets when factored in with the previous works on this topic.
In alignment with results from prior studies, we also found that the use of a breast cup provides a significant benefit with regard to treatment planning for organs at risk, namely the heart. In the study by Joseph et al,11 which demonstrated the MHD among a group of patients with left-sided breast cancer who received adjuvant radiation either with or without a breast cup, the MHD proved to be 2.15 versus 5.15 Gy, respectively.11 Our analysis of the MHD showed that patients treated with a breast cup were found to have an MHD of 1.7 Gy. Specifically, patients with left-sided breast cancer who were irradiated with the use of a breast cup had an average MHD of 2.3, whereas the MHD was 2.2 in the left-sided breast cancer patients treated without a cup (Table 3). Although these values prove to be very similar, we still interpret our results to be highly significant. Every patient in our cohort who was treated with a breast cup had larger and more pendulous breasts, which are factors that historically led to radiation plans with higher MHDs. Patients who were treated without a cup had breasts that were naturally smaller and positioned more medially/anteriorly. Therefore, the near equivalent MHD values between our subsets of patients with left-sided breast cancer show that the ability to position a breast more medially and anteriorly with a breast cup provides desirable dosimetric outcomes that are comparable to radiation plans for patients with breast cancer with naturally existing favorable anatomy.
Table 3.
Mean heart dose
| Laterality | Breast cup use | N | Minimum | Mean | Median | SD | Maximum |
|---|---|---|---|---|---|---|---|
| Left | No | 277 | 0.0 | 2.2 | 2.1 | 1.0 | 5.3 |
| Yes | 47 | 0.1 | 2.3 | 2.0 | 1.2 | 6.4 | |
| Right | No | 289 | 0.0 | 0.6 | 0.5 | 0.5 | 6.4 |
| Yes | 32 | 0.3 | 0.6 | 0.5 | 0.3 | 2.0 |
Our results further solidify and validate the principle that patient-reported toxicity to breast RT for patients with larger, pendulous breasts treated with a breast cup is similar to those that do not require its use. Given that many previously reported publications have noted greater treatment-related toxicity in women with larger breasts, especially in patients within the Black/African American community, the use of a breast cup helps to decrease the disparity in treatment-related side effects. Mainly, this would be due to the higher incidence of inframammary fold skin toxicity that can occur in larger-breasted women treated with breast RT when no breast cup is used. As such, our data most certainly show that breast cup use does not harm the patient. In fact, we believe it provides an even greater benefit than our PROs show.
With regard to the potential shortcomings of this analysis, the patient groups were not randomized. Instead, patients were chosen to be treated with a breast cup based on physician discretion at the time of physical examination during the consult visit, with the larger and more pendulous breasts more often selected for breast cup use. However, even with the majority of the breast cup group consisting of larger-breasted women, patient-reported breast toxicity differences between treatment groups were statistically insignificant. This is an encouraging fact because it has previously been determined that larger- breasted women can be found to be at greater risk of radiation-associated skin toxicity among non-breast cup-treated patients.12 Therefore, we think that the potential shortcoming of the lack of randomization actually strengthens the argument for the support of breast cup use because the patient population selected for breast cup use is historically known to have greater challenges with breast RT (both in toxicity and treatment planning). We would also like to acknowledge our awareness of missing PROs identified in Table 2. PROs were collected from patients using paper forms and all of the questions were not always completed. In addition, during the time span of this study, 2011-2019, the PROs evaluated were further developed and adjusted. Therefore, we do not have the same PRO responses from patients enrolled at different points of the study.
Conclusions
From our patients’ perspective, the use of a breast cup during RT does not negatively impact breast cosmesis or pain when compared with patients treated without a cup. Furthermore, breast cup use was also found to yield an overall comparable mean heart dose when compared with non-cup-treated patients. This is an encouraging and important finding because mean heart doses were historically much higher in larger-breasted patients, such as those in the breast cup cohort, when they were given breast irradiation without the use of a breast cup. Additionally, given the cosmetic and dosimetric benefits of a breast cup, further dissemination of breast cup use is expected to help decrease disparities in breast cancer care for Black/African American women because this population makes up a significant component of the patient population with naturally larger breasts. In conclusion, we recommend using a breast cup when treating women with pendulous breasts with RT given the treatment planning benefits and favorable patient outcomes.
Disclosures
There are no conflicts of interest to report.
Footnotes
Sources of support: No funding was received to complete this analysis.
Data sharing statement: Research data are mostly present within this editorial. Additional research data are stored in an institutional repository and will be shared on request to the corresponding author.
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