Targeted therapies for cancer of the gallbladder

Association of BDNF and BMPR1A with clinicopathologic parameters in benign and malignant gallbladder lesions

BACKGROUND

Neurotrophic factors such as brain derived neurotrophic factor (BDNF) are synthesized in a variety of neural and non-neuronal cell types and regulate survival, proliferation and apoptosis. In addition, bone morphogenetic proteins (BMPs) inhibit the proliferation of pulmonary large carcinoma cells bone morphogenetic protein receptor, type IA (BMPR1A). Little is known about the expression of BDNF or BMPR1A in malignant gall bladder lesions. This study was to evaluate BDNF and BMPR1A expression and evaluate the clinicopathological significance in benign and malignant lesions of the gallbladder.

METHODS

The BDNF and BMPR1A expression of gallbladder adenocarcinoma, peritumoral tissues, adenoma, polyp and chronic cholecystitis were Immunohistochemically determined.

RESULTS

BDNF expression was significantly higher in gallbladder adenocarcinoma than in peritumoral tissues, adenoma, polyps and chronic cholecystitis samples. However, BMPR1A expression was significantly lower in gallbladder adenocarcinoma than in peritumoral tissues, adenomas, polyps and chronic cholecystitis tissues. The specimens with increased expression of BDNF in the benign lesions exhibited moderate- or severe-dysplasia of gallbladder epithelium. BDNF expression was significantly lower in well-differentiated adenocarcinomas with maximum tumor diameter <2 cm, no metastasis to lymph nodes, and no invasion of regional tissues compared to poorly-differentiated adenocarcinomas with maximal tumor diameter >2 cm, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma. BMPR1A expression were significantly higher in the well-differentiated adenocarcinoma with maximal tumor diameter <2 cm, no metastasis of lymph node, and no invasion of regional tissues compared to poorly-differentiated adenocarcinomas with maximal tumor diameter >2 cm, metastasis of lymph node, and invasiveness of regional tissues in gallbladder. Univariate Kaplan-Meier analysis indicated increased expression of BDNF or decreased expression of BMPR1A was associated with decreased disease specific survival (DSS) rates. Similarly, multivariate Cox regression analysis showed increased expression of BDNF or decreased expression of BMPR1A are independent predictors of poor DSS rates in gallbladder adenocarcinoma.

CONCLUSIONS

In gallbladder malignancies, the increased expression of BDNF and decreased expression of BMPR1A were associated with increased risk of metastasis, regional invasion and mortality. They might serve as novel indicators of gallbladder adenocarcinoma outcomes, which may prove valuable for the development of personalized therapeutic paradigms.

Recent advances in systemic therapies and radiotherapy for gallbladder cancer

Adjuvant treatment is not routine following resection for gallbladder cancer as most regimens have low response rates. In the palliative setting, recent advances have been made regarding combination chemotherapies and both gemcitabine/cisplatin and gemcitabine/oxaliplatin appear to be superior to single-agent 5FU, which has very little efficacy in this disease. There are isolated reports of dramatic responses to targeted monoclonal agents. The role of radiotherapy has recently been revisited, however, its effectiveness when patients are adequately surgically treated remains to be demonstrated.