The Diverse Effects of Histopathology on Manifestations and Outcome of Lung Cencer

¹ Professor of Medicine and Epidemiology, Yale University School of Medicine, New Haven; Chief, Clinical Biostatistics and Co-Operative Studies Program Support Center, Veterans Administration Hospitla, West Haven
² Pathologist, West Haven Veterans Administration Hospital; Assistant Professor of Pathology, Yale University School of Medicine
³ Chief of Staff and Chief, Laboratory Service, West Haven Veterans Administration Hospital; Associate Dean and Professor of Pathology, Yale University School of Medicine

The manifestations and outcome of lung cancer in 449 patients have been correlated with the new WHO histologic classifications. The six main histologic groupings were: well-differentiated epidermoid, poorly-differentiated epidermoid, well-differentiated adenocarcinoma, poorly-differentiated adenocarcinoma, large cell undifferentiated, and small cell undifferentiated. The biologic behavior of the well-differentiated and poorly-differentiated groups seemed relatively similar for epidermoid carcinomas, but was substantially different for adenocarcinomas. Adenocarcinomas occurred most commonly among women, and were most likely to be detected either while asymptomatic or after manifest metastasis. Epidermoid carcinomas were likely to present with a bronchoscopically visible mass, with the "primary" symptom of cough or hemoptysis, and with positive tests for sputum cytology. The mean age at diagnostic detection was similar in all six histologic subgroups, but the mean duration of pretherapeutic symptoms was longer in the epidermoid group than in the others. The epidermoid cancers had the lowest rates of pretherapeutic metastasis, the highest rates of operability and resectability, and the highest overall survival rates. The lowest rates of operability, resectability, and overall survival were in small cell undifferentiated cancers and in poorly-differentiated adenocarcinomas. A striking finding among inoperable patients was that sixmonth survival rates depended much more on symptomanatomic stage than on histologic type.