{"entity":{"id":"lung-adenocarcinoma-in-situ-and-minimally-invasive","kind":"cancer","name":"Adenocarcinoma in situ and minimally invasive adenocarcinoma of the lung","aka":["Adenocarcinoma in situ of the lung","AIS","Minimally invasive adenocarcinoma","MIA","Lepidic adenocarcinoma, preinvasive","Bronchioloalveolar carcinoma (term retired in 2011)","Ground-glass nodule adenocarcinoma"],"tldr":"Adenocarcinoma in situ and minimally invasive adenocarcinoma are the earliest forms of lung cancer of the adenocarcinoma type: small tumours, usually seen as ground-glass spots on a CT scan, that have not yet invaded, or have invaded less than five millimetres. When removed they are effectively cured, with no recurrences in the large series, so the question is how little surgery is enough.","summary":"The IASLC/ATS/ERS classification introduced adenocarcinoma in situ (a solitary adenocarcinoma of 3 cm or less with pure lepidic growth along intact alveolar walls) and minimally invasive adenocarcinoma (the same with an invasive component of 5 mm or less) in place of the term bronchioloalveolar carcinoma, and the WHO classifications of 2015 and 2021 keep both entities and stage them by invasive size only (Travis 2011; Nicholson 2022). They present as ground-glass or part-solid nodules on CT.\n\nHow it differs from its parent: outcome. In 1,038 stage I adenocarcinomas, none of the 36 patients with adenocarcinoma in situ or minimally invasive adenocarcinoma recurred, lepidic predominant invasive tumours had a five-year cumulative recurrence of 8 percent, and non-lepidic tumours 19 percent (Kadota 2014). In 524 resected cases in Japan (65 percent women, 64 percent never-smokers, mean tumour diameter 15.2 mm, 44 percent treated by sublobar resection) there was no recurrence over a median follow-up of 100 months, and the clinical problem was second primary lung cancers rather than relapse (Yotsukura 2021).\n\nHow common: about 11 percent of lung cancers coming to resection in the Japanese series (Yotsukura 2021); a growing share where CT screening is used.\n\nTreatment: surgical removal, increasingly by sublobar resection (wedge or segmentectomy) rather than lobectomy, with no adjuvant therapy; the parent's resectable page holds the trials of sublobar surgery for small peripheral tumours (CALGB 140503, JCOG0802). Small pure ground-glass nodules are often watched on CT before any surgery.","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/Adenocarcinoma_of_the_lung","links":[{"label":"Travis 2011, JTO: IASLC/ATS/ERS international multidisciplinary classification of lung adenocarcinoma","url":"https://doi.org/10.1097/jto.0b013e318206a221"},{"label":"Nicholson 2022, JTO: the 2021 WHO classification of lung tumours","url":"https://doi.org/10.1016/j.jtho.2021.11.003"},{"label":"Kadota 2014, Am J Surg Pathol: prognosis of adenocarcinoma in situ, minimally invasive and lepidic predominant adenocarcinoma in 1,038 stage I cases","url":"https://doi.org/10.1097/pas.0000000000000134"},{"label":"Yotsukura 2021, JTO: long-term prognosis of 524 resected adenocarcinoma in situ and minimally invasive adenocarcinoma","url":"https://doi.org/10.1016/j.jtho.2021.04.007"}],"tags":["subtype-page","wave4","lung"],"related":["nsclc","lung-adenocarcinoma","resectable-nsclc","invasive-mucinous-adenocarcinoma-lung"],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["lobectomy"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"group":"lung","burden":"Of 1,038 resected stage I adenocarcinomas at Memorial Sloan Kettering, 2 were adenocarcinoma in situ and 34 minimally invasive (Kadota 2014); of 4,768 lung cancer resections in Japan between 1998 and 2010, 524 (11 percent) were one or the other (Yotsukura 2021).","subtypes":["Adenocarcinoma in situ, non-mucinous (pure lepidic, 3 cm or less)","Minimally invasive adenocarcinoma, non-mucinous (invasion 5 mm or less)","Mucinous adenocarcinoma in situ and minimally invasive adenocarcinoma (rare)","Lepidic predominant invasive adenocarcinoma (over 5 mm invasion; not preinvasive)"],"biomarkers":["Invasive size on the resection specimen (5 mm threshold)","Ground-glass and solid components on CT","EGFR mutation (common in lepidic tumours; not treated at this stage)"],"standardOfCare":[{"setting":"All cases","approach":"Surgical resection, sublobar where the tumour is small and peripheral, with no adjuvant therapy; the parent's resectable page holds the sublobar-surgery trials.","refs":["resectable-nsclc","lobectomy"]}],"stateOfArt":[],"history":[],"pipeline":[],"openProblems":[],"parent":"nsclc"},"route":"/cancers/lung-adenocarcinoma-in-situ-and-minimally-invasive/","neighbours":{"cancer":[{"id":"lung-adenocarcinoma","kind":"cancer","name":"Adenocarcinoma of the lung","route":"/cancers/lung-adenocarcinoma/"},{"id":"invasive-mucinous-adenocarcinoma-lung","kind":"cancer","name":"Invasive mucinous adenocarcinoma of the lung","route":"/cancers/invasive-mucinous-adenocarcinoma-lung/"},{"id":"nsclc","kind":"cancer","name":"Non-small-cell lung cancer","route":"/cancers/nsclc/"},{"id":"resectable-nsclc","kind":"cancer","name":"Resectable stage I to III non-small-cell lung cancer","route":"/cancers/resectable-nsclc/"}],"term":[{"id":"lobectomy","kind":"term","name":"Lobectomy","route":"/terms/lobectomy/"}]}}