Table 1.
Main characteristics of the studies included in the systematic review and meta-analysis on the prognostic effect of quitting smoking at or around diagnosis on the survival of bladder cancer patients.
| Author, Year | Country | Sex (% Men) | Age (Years) | No. Patients (a) | Smoking Status | Years of Diagnosis | Tumour Stage | Treatments | Follow-Up (Years) | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Non-Smokers at Diagnosis (b) | Continued Smokers | Quitters | |||||||||
| Serretta, 2021 [24] | Italy | NA | Median 63 (range 57–70) | 194 | 0 (0.0%) | 127 (65%) | 67 (35%) | 2008–2012 | Ta (57%), T1 (37%), Tis (6%) | TUR (100%) | Median 5.7 (range 0.5–4.4) |
| van Osch, 2018 [25] | UK | 79% | Median 71 (IQR 63–77) | 722 | 519 (72%) | 186 (26%) | 17 (2%) | 2005–2011 | pTa (66%), pT1 (33%), pCis (1%) | TUR (100%) | Median 4.2 (IQR 2.7–5.0) |
| Koshiaris, 2017 [26] | UK | 74% | Mean 66.9 | 1733 (c) | 0 (0.0%) | 850 (49%) | 356 (21%) | 1999–2013 | NA | surgery (9%), CT (15%), RT (4%) | Na |
| Grotenhuis, 2015 [27] | Netherlands | 82% | Mean 63.3 (range 25–92) | 963 (d) | 671 (70%) | 194 (20%) | 71 (7%) | 1995–2010 | Ta (69%), T1 (26%), Cis (4%), unknown (1%) | TUR only (46%), adjuvant CT (32%), adjuvant IT (21%), adjuvant CT + IT (1%), other or unknown (<0.01%) | Median 3.7 (IQR 2.7–4.7) |
| Tao, 2013 [28] | China | 100% | Na | 107 (e) | 58 (54%) | NA | NA | 1986–2010 | NA | NA | Mean 5.3 |
| Lee, 2012 [29] | South Korea | 90% | Mean 62.2 | 597 | 337 (56%) | 159 (27%) | 101 (17%) | 1989–2008 | ≤T2 (57%), >T2 (43%) | radical cystectomy (100%) | Median 4.7 (range 0.2–18.9) |
| Sfakianos, 2010 [30] (f) | USA | 68% | Median 76 | 623 | 485 (77%) | 97 (16%) | 41 (7%) | 1994–2008 | Ta (35%), T1 (35%), Tis (30%) | TUR + intravesical BCG (100%) | Median 6.7 |
| Chen, 2007 [31] | Taiwan | 100% | Median 67 (range 36–90) | 265 | 128 (48%) | 78 (30%) | 59 (22%) | 1997–2005 | Ta (62%), T1 (38%) | TUR (100%), chemotherapy (58%), BCG (19%) | Median 3.2 (range 0.3–9.4) |
| Fleshner, 1999 [32] (f) | USA | 80% | Mean 61.2 (range 29–85) | 286 | 127 (44%) | 108 (38%) | 51 (18%) | 1985–1995 | Ta (52%), T1 (31%), Tis (17%) | TUR (100%), initial BCG therapy (23%) | Mean 4.8 (range 0.2–10.9) |
(a) This refers to the patients included in the analyses aimed at estimating the effect of at/around smoking cessation on cancer survival or recurrence (it may be lower than the total number of patients in the study). (b) This category includes never smokers and long former smokers. (c) For 527 patients (30% of the total), the smoking status during the first year of follow-up (continued/quitter) was unknown and imputed via multiple imputations. (d) The smoking status (continued/quitter) of 27 patients who were smoking at diagnosis was not known. (e) The breakdown of the 49 active smokers at diagnosis (46%) into continued smokers and quitters was not specified. (f) The studies by Sfakianos et al. 2010 and Fleshner et al. 1999 were conducted at the same hospital (Memorial Sloan-Kettering Cancer Center, New York, USA) and included bladder cancer patients’ diagnoses during 1994–2008 and, respectively, from 1985–1995, so a minor overlapping of the study samples cannot be ruled out. NA: not available. TUR: transurethral resection. CT: chemotherapy. RT: radiotherapy. IT: immune therapy. BCG: bacillus Calmette-Guérin.