A case of pulmonary adenocarcinoma with overexpression of multidrug resistance-associated protein and p53 aberration

A 66-year-old female patient underwent left upper lobectomy and dissection of the mediastinal lymph nodes. The pathological diagnosis was well-differe ntiated papillary adenocarcinoma of the lung with metastasis to the mediast inal lymph nodes, p-T2N2MO, stage IIIA. After the operation she was treated by chemotherapy including lipophilic anticancer compounds (carboplatin and VP- 16). The patient unexpected by showed long survival for 6 years and 2 months without obvious recurrence or metastasis of the cancer. The anticanc er compounds were not effective on the recurrent lesions and then she died doe to respiratory failure 8 months after recurrence The autopsy revealed p leural dissemination and intrapulmonary metastasis. Immunohistochemical ana lysis showed increased multidrug resistance-associated protein (MRP)-positi ve tumor cells in the recurrent and metastatic lesions, while few MRP-posit ive cells were apparent in the primary lesion. The MRPpositive cells were a ccompanied by p53 nuclear accumulation in the carcinoma. This was a case of pulmonary adenocarcinoma with acquired multidrug resistance caused by MRP overexpression and aberrant p53 after chemotherapy.