Abstract
Background. Pemetrexed is an effective anticancer agent for patients with advanced non-small cell lung cancer (NSCLC). Few reports have described the appearance of a new lesion with a squamous histology during long term pemetrexed treatment in a patient with large cell carcinoma. Case. A 75-year-old man was diagnosed as having large cell carcinoma and underwent surgery. The pathological stage was T1aN1M0. Accordingly, he received adjuvant chemotherapy using cisplatin and vinorelbine. However, he was diagnosed as having recurrent disease with multiple pulmonary metastases, subcarinal lymph nodes metastases and multiple bone metastases. Accordingly, he received pemetrexed monotherapy and was able to complete 22 cycles of the regimen. Although reductions in the multiple pulmonary metastases were observed, a newly formed lesion was seen in the right upper lobe. This new lesion subsequently increased in size. A CT-guided needle biopsy of the new lesion was performed, and the lesion was diagnosed pathologically as a squamous cell carcinoma of the lung. He was treated with stereotactic radiosurgery for squamous cell carcinoma. Conclusion. It was possible to confirm that anticancer efficacy of pemetrexed was varied according to histological types by rebiopsy for new lesion.
