This paper presents a rare case of an elderly patient treated with
erlotinib for disseminated
lung adenocarcinoma with poor performance status (Eastern Cooperative Oncology Group performance status [PS]3). This treatment led to a long duration of complete remission according to Response Evaluation Criteria in Solid Tumors 1.1 - almost 7 years (81 months) of progression-free survival (PFS) and overall survival (OS) of 10 years by March 2017. The treatment with
erlotinib started in September 2008 and it was well tolerated with no adverse effects. Mutation analyses (real-time polymerase chain reaction method) revealed deletion of EGFR (
epidermal growth factor receptor) gene and wild-type Kirsten-
ras protein gene in exon 19. In May 2015, the patient relapsed with
jaundice and enlarged lymph nodes of the liver hilum, with no other
metastasis, PS 2. Biopsy confirmed
metastasis of
lung adenocarcinoma. EGFR molecular testing did not reveal T790M mutation. Treatment was continued with
gemcitabine-
cisplatin chemotherapy. A total of six cycles were administered with nearly complete response and Eastern Cooperative Oncology Group performance status 0. Further on,
gemcitabine monotherapy has been administered with nearly complete response maintained and OS of 10 years by March 2017. This report describes an extremely rare case of a poor performance patient with advanced metastatic
adenocarcinoma harboring EGFR mutation - deletion in exon 19 - who was receiving salvage
erlotinib and had a complete response with 81 months of PFS followed by a relapse and subsequent
chemotherapy which led to nearly complete response, with an OS of 10 years by March 2017. Such a complete response to
tyrosine kinase inhibitor therapy in a poor PS patient, with long PFS and OS achieved, justifies
tyrosine kinase inhibitor treatment approach in poor PS patients with EGFR-sensitizing
tumors, and furthermore points to the feasibility of administering
chemotherapy at the time of relapse.