With advancements in cancer treatments, the survival rates of patients with their first primary cancer (FPC) have increased, resulting in a rise in the number of patients with second primary cancer (SPC). However, there has been no assessment on the incidence of suicide among patients with SPC. This study assessed the occurrence of suicide among patients with SPC and compared them with that in patients with FPC.

This was a retrospective, population-based cohort study that followed patients with FPC and SPC diagnosed from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) 17 registries database between 1 January 2000 and 31 December 2019.

For patients with SPC, an age of 85+ years at diagnosis was associated with a higher incidence of suicide death (HR, 1.727; 95% CI, 1.075–2.774), while the suicide death was not considerably different in the chemotherapy group (P > 0.05). Female genital system cancers (HR, 3.042; 95% CI, 1.819–6.361) accounted for the highest suicide death among patients with SPC. The suicide death distribution of patients with SPC over time indicated that suicide events mainly occurred within 5 to 15 years of diagnosis. Compared with patients with FPC, patients with SPC in general had a lower risk of suicide, but increased year by year.

The risk of suicide was reduced in patients with SPC compared with patients with FPC, but increased year by year. Therefore, oncologists and related health professionals need to provide continuous psychological support to reduce the incidence of suicide. The highest suicide death was found among patients with female genital system cancer.

To explore the risk factors associated with the occurrence of synchronous oesophageal cancer in patients with hypopharyngeal cancer, and to investigate the roles of image-enhanced endoscopic screening in the prediction and diagnosis of early oesophageal cancer.

The clinical characteristics of patients with hypopharyngeal cancer (n = 160) were analysed. All patients underwent laryngoscopic and gastroscopic examination using image-enhanced endoscopic techniques before treatment.

Of 160 hypopharyngeal cancer patients, 43 (27 per cent) had synchronous oesophageal cancer. Heavy drinking (odds ratio = 4.787, p = 0.029) and local invasion of three or more anatomical sites (odds ratio = 14.391, p = 0.000) were independent risk factors for synchronous oesophageal cancer. Narrow-band imaging laryngoscopy could detect more invaded anatomical sites than ordinary white light endoscopy (t = 8.532, p = 0.000). More early oesophageal cancer cases were detected with Lugol chromoendoscopy than with non-Lugol iodine staining examination (χ2 = 4.925, p = 0.026).

Synchronous oesophageal cancer is common in patients with hypopharyngeal cancer. The heavy drinking patients with hypopharyngeal cancer should undergo intensive monitoring. Image-enhanced endoscopic screening is helpful in the prediction and early detection of second primary oesophageal cancer.