Stage 1a2 squamous lung cancer is generally not in situ squamous lung cancer, but early squamous lung cancer. In situ squamous lung cancer generally means that the cancer tissue has not broken through the basement membrane and the lesions are relatively limited. Stage 1a2 squamous lung cancer has already invaded the basement membrane, but the cancer foci are relatively small, usually less than 3 centimeters in diameter, and there is no dissemination to the surrounding lymph nodes and distant organs, so it still belongs to early squamous lung cancer. Stage 1a2 squamous lung cancer generally has no contraindication to surgery, radical surgery can be taken to remove the tumor, and most of the patients do not need adjuvant chemotherapy after surgery. Patients with contraindication to surgical treatment can consider radical radiotherapy to control squamous lung cancer. It is suggested that patients with squamous lung cancer should go to professional hospitals as soon as possible and listen to the opinions of professional doctors.