DISCUSSION
Smoking is a significant risk factor for BC. It is a rich source for aromatic amines and nitroso compounds which have carcinogenic effect on bladder by damaging the DNA.7 In a meta-analysis, the relative risk of BC was found to be 3.47(95% confidence interval [CI] 3.07–3.91) for current smokers compared to non-smokers. Even the relative risk of BC for ex-smokers was 2.04 (95% confidence interval [CI] 1.85-2.25) compared to non-smokers.4The rate of patients who never smoked was 12.7% and the rate of still smokers were 41.6% in our study population. This data was not surprising that nearly 90% of our patients were still smokers or former smokers at the time of diagnosis.
The relation of smoking and the BC is a well-known phenomenon for the clinicians; on the other hand, patients learn this reality as soon as they are diagnosed as BC. At this situation all of the BC patients are advised to give up smoking. The main question is “do the patients really understand the importance of cessation of smoking and do they really give up smoking?” Nearly 40% of our study population was current smoker at the time of diagnosis. Two third of these patients were still smokers with a mean follow-up time of 37 months. All of the patients informed about the importance of cessation of smoking for their both general health and BC several times, but it was surprising that most of the patients did not understand this reality. Although the post-diagnosis smoking frequency decreased significantly compared to pre-diagnosis smoking frequency, the current smokers were still smoking 11 cigarettes per day. Similar results were also seen at Sfakianos et al study. In their 623 patient series, 138 patients were smoker at the time of diagnosis. The authors showed that 70% of patients were still smoker in a median follow-up of 80 months.13 This data documented that only informing the patients to stop smoking is not enough to achieve the goal. Professional support and close follow-up might be necessary.
According to our knowledge this is the first study evaluating the postoperative time that the BC patients stopped smoking and the reason of this behavior. Nearly two thirds of the smoking quitters stopped smoking at the first month of their diagnosis. After this period, the rate of cessation of smoking decreased significantly. This behavior might be related with the immediate anxiety of the patients as they realized their disease. After a period of time, patients might get use to their disease and lose their apprehension to stop smoking. Nearly all the patients who gave up smoking after the diagnosis of BC declared that the reason was the diagnosis of BC. According to our study, the initial months of the BC diagnosis was very important for the patients to give up smoking and for the clinicians to achieve their goal. As the time passed, the probability of patients to stop smoking also decreased. For that reason, a professional work-up might be necessary as soon as the diagnosis was made. By this way, clinicians may increase their chance to ensure their patients to give up smoking.
The effect of smoking on disease recurrence and progression is debatable. Simonis et al stated that smoking status increased the risk of BC recurrence and progression. The authors concluded that heavy long-term smokers and patients who did not quit smoking were at risk for both recurrence and progression.14 On the other hand, Sfakianos et al reported that smoking status was not associated with BCG response, disease recurrence and disease progression.13 In another study, Kim et al also reported that smoking status was not a significant factor for BC recurrence.15 Similar to these findings, van Osch et al reported that although the smoking cessation indicated a protective association with BC recurrence, the statistical analysis was not significant and the authors concluded that this relation could not be considered as strong.16-17 We also observed that cessation of smoking was not related with BC recurrence and progression. The rate of recurrence and progression was similar at patients who stopped smoking after the diagnosis compared to still smokers.
Smoking status is also important for patients with MIBC.18 Rink et al revealed that smoking status was associated with disease recurrence and cancer specific mortality at radical cystectomized patients.19 Cacciamani et al stated that smoking was associated with lower neoadjuvan chemotherapy response before radical cystectomy. In addition, they also revealed smoking was related with higher recurrence and disease specific mortality rates at radical cystectomy patients.20 As the authors showed it, stopping smoking was very important for patients with MIBC. We were expecting to find high rates of cessation of smoking in MIBC patients because these patients had to deal with major treatment protocols, which changed their life significantly. And the major responsible for this situation was smoking. Surprisingly the rate cessation of smoking among these patients was only 27.3 %. This data documented that patients with MIBC insisted to smoke and the clinicians was not successful in terms of making their patients smoke-free. However, we predicted the smoking cessation rates would be higher. Because the patients follow up were more frequent so they had exposed much more suggestion about smoking cessation from our medical team. In addition, radical cystectomy is not a simple operation; it is the major oncological surgery. Therefore, the rates of cessation of smoking were far below our expectations and consequently the radical cystectomy patients should be much more encouraged for smoking cessation.
Our study had some limitations. The mean follow-up period of our study population was 37 months, which might be a short period of time. On the other hand, the main aim of this study to evaluate the rate and the time of cessation of smoking in which the follow-up period might be significant. The status of smoking was documented by self-reported questionnaire, which may be another limitation of the study. In order to overcome this possible personal bias, we cross-questioned the close relatives about the smoking habit of the patient. If there was an inconsistency about the answers patients were re-questioned.