Therapeutic effect of intravesical administration of paclitaxel solubilized with poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) in an orthotopic bladder cancer model.

BACKGROUND: To evaluate the effects of intravesical administration of paclitaxel (PTX-30W), which was prepared by solubilization with a water-soluble amphiphilic polymer composed of PMB30W, a copolymer of 2-methacryloyloxyethyl phosphorylcholine and n-butyl methacrylate, in an orthotopic bladder cancer model. METHODS: The cytotoxicities of PMB30W were examined in MBT-2 cell cultures and the results were compared with those of the conventional paclitaxel solubilizer Cremophor. In an orthotopic MBT-2 bladder cancer model, the effect of intravesical administration of PTX-30W was compared with that of paclitaxel solubilized with Cremophor (PTX-CrEL). The paclitaxel concentration in bladder tumors after the intravesical treatment was also evaluated using liquid chromatography tandem mass spectrometry (LC-MS/MS) system. RESULTS: In vitro, Cremophor exhibited dose-dependent cytotoxicity towards MBT-2 cells, whereas no cytotoxicity was observed with PMB30W. In the orthotopic bladder cancer model, intravesical administration of PTX-30W resulted in a significant reduction of bladder wet weight compared with that of PTX-CrEL. The paclitaxel concentration in bladder tumors after the intravesical treatment was significantly higher in PTX-30W treated mice than in PTX-CrEL treated mice. CONCLUSIONS: Intravesically administered PTX-30W can elicit stronger antitumor effects on bladder tumors than conventional paclitaxel formulated in Cremophor, presumably because of its better penetration into tumor cells. PTX-30W might be a promising antitumor agent for intravesical treatment of non-muscle invasive bladder cancer.

[IPSILATERAL SYNCHRONOUS MUCINOUS TUBULAR AND SPINDLE CELL CARCINOMA AND CLEAR CELL PAPILLARY RENAL CELL CARCINOMA: A CASE REPORT AND REVIEW OF THE LITERATURE].

Renal cell carcinoma (RCC), the most common solid lesion of the kidney, accounts for approximately 2%-3% of all malignancies among adults. Clear cell carcinoma and papillary cell carcinoma are the most common types of renal tumors. Some case reports have described synchronous benign and malignant tumors in the same kidney. In particular, angiomyolipoma and RCC in patients with tuberous sclerosis (TSC) and non-TSC have been reported many times in the literature. However, unilateral concordance of malignant renal tumors is very rare; thus, only few cases have been reported in the literature.Here we report the case of a 58-year-old male who had ipsilateral synchronous mucinous tubular and spindle cell carcinoma (MTSCC) and clear cell papillary renal cell carcinoma (CCPRCC). Both cancers are rare and relatively recently defined subtypes of RCC. Additionally, both were successfully treated using partial nephrectomy. MTSCC has been a distinct entity in the World Health Organization classification of kidney tumors since 2004. The classic type of MTSCC is characterized by small elongated tubules lined with clear cuboidal or spindle cells with mucinous stroma. Neoplastic cells always exhibit low-grade histological features. However, unclassified variants of MTSCC, such as mucin-poor, papillary, high-grade, and sarcomatoid variants, have also been reported. MTSCC is considered to have a relatively good prognosis, but some patients with poor prognoses have recently been reported. CCPRCC is a recently recognized entity and represents the fourth most common variant of RCC. It has unique morphological and immunohistochemical features and shows indolent clinical behavior. Microscopically, CCPRCC may mimic other RCCs with clear cell features, such as clear cell RCC, translocation RCC, and papillary RCC, with clear cell changes. In 2006, CCPRCC was described as a subtype of renal tumors in patients with end-stage renal disease. However, currently, CCPRCC has also been shown to occur in kidneys with normal function.To the best of our knowledge, this is the first report of ipsilateral synchronous MTSCC and CCPRCC, which we present with a review of the pertinent literature.

[A case of small cell carcinoma in a diverticulum of the bladder].

We report a case of small cell carcinoma in a diverticulum of the bladder. A 64-year-old Japanese man visited our hospital with the chief complaint of urinary retention. Cystoscopy revealed a papillary tumor arising in a diverticulum on the right lateral wall of the bladder. Partial cystectomy was performed under the diagnosis of bladder cancer in the diverticulum. The histopathological diagnosis was a combination of small cell carcinoma and urothelial carcinoma, of which the former was dominant. It is often difficult to detect tumors in the bladder diverticula and its early penetration is not rare because of the thin wall. Therefore, the prognosis of the bladder cancer in the diverticulum is believed to be generally poor. On the other hand, small cell carcinoma originating in the urinary bladder is also characterized by its extreme rareness and poor prognosis. To our knowledge, this is the second case report of the small cell carcinoma arising in a diverticulum of the urinary bladder in the Japanese literature.