AB061. Clinical analysis of small cell carcinoma of the bladder: 9 cases report and literature review

Objective: To present our experience with nine patients with small cell carcinoma of the bladder (SCCB) who were treated with different modalities and review the literature for patients with SCCB who have been reported in 56 literatures. SCCB is a rare, highly aggressive tumor that presents in an advanced stage and has a propensity for early metastasis. Hematuria is the main clinical manifestations. Surgery, chemotherapy, and radiotherapy, either alone or as part of combined therapy have been used for treatment.

Methods: We retrospectively evaluated nine patients with SCCB by medical record review between February 1980 and January 2014 at Tongji Hospital of Huazhong University of Science and Technology. In order to better understand the clinical features of SCCB, 56 literatures were concerned (from January 1979 to March 2014). The general characteristics, clinical manifestation, the pathological and immunohistochemical characteristics, treatment options and prognostication in those eligible manuscripts are analyzed, a retrospective analysis is performed.

Results: All the nine cases in Tongji hospital were successfully operated and tissue samples were carried on pathological examination. All the tumor tissue contained small cell carcinoma components, there were four cases coexisting with other histologic types of bladder cancers, and 2 of the 9 cases have three different cell components. All patients had muscle-invasive disease at presentation, 4 cases showed lymph nodes metastasis, 3 cases showed invasion of the surrounding seminal vesicle or uterus, and 1 case greatly suspected the liver metastasis. Specimens of all cases underwent immunohistochemistry examination showed that NSE, PCK, Syn, and CD56 were all positive, but LCA was negative. After operation, 3 patients underwent chemotherapy and only one patient received post operational radiotherapy. Patients were followed up range between 3 to 84 months and the median survival time was 33 months. The main reasons of the patients die are tumor recurrence and metastasis, but two patients are still alive.

Conclusions: SCCB is different from transitional cell carcinoma (TCC) of the bladder. It has its unique cytology, immunohistochemistry and ultrastructural features. Diagnosis depends on pathological examination and immunohistochemistry. Surgery followed by chemotherapy is the main treatment method currently. In view of the disease is easily early metastasis, the overall prognosis for this cancer is poor. Further research is required to understand the molecular pathogenesis so that novel targeted therapies can be developed for this rare cancer.

Keywords: Bladder cancer; small cell carcinoma; neuroendocrine carcinoma; chemotherapy