Impact of smoking on multiple primary cancers survival: a retrospective analysis

According to available literature, active tobacco smoking enhances the risks of recurrence and development of new primary malignancies. Smoking also shortens the survival period for patients with a diagnosed neoplastic disease. Medical records of 1622 patients hospitalized at the Center for Pulmonary Diseases from January 2013 till March 2017 were retrospectively analyzed, out of which 741 cases with a diagnosis of at least one primary cancer were selected, including 111 patients with multiple primary malignancies. Survival time, the impact of smoking on cancer development and the influence of smoking cessation on the prognosis of the development of new malignancies were analyzed. The incidence of multiple primary malignancies in the population of cancer patients amounted to 14.98%. In the group of smokers, those who ceased smoking developed the second primary malignancy later as compared to those who did not: the period between the first and the new cancer was 11.55 years (SD 7.24) for those who quit smoking, whereas for those who continued to smoke after their first cancer diagnosis it was 6.10 years (SD 8.62) (p = 0.005). It was revealed that patients who had never smoked lived longer than those who had continued to smoke (p = 0.004) and that those who had ceased smoking had a longer survival time than those who had not (p = 0.027). Ceasing smoking after the first cancer diagnosis prolongs the time before a new malignancy develops and is diagnosed, as well as the total survival time after the first cancer diagnosis.