Lung Cancer Reporting (Biopsy/Cytology Specimens)

Measure Specification

Lung cancer is the most frequent cause of major cancer incidence and mortality worldwide. The classifications of lung cancer published by the World Health Organization (WHO) in 1967, 1981, and 1999 were written primarily by pathologists for pathologists. Only in the 2004 revision, relevant genetics and clinical information were introduced. Nevertheless, because of remarkable advances over the last 6 years in our understanding of lung adenocarcinoma, particularly in the area of medical oncology, molecular biology, and radiology, there is a pressing need for a revised classification, based not on pathology alone, but rather on an integrated multidisciplinary platform.

For the first time, this classification addresses an approach to small biopsies and cytology in lung cancer diagnosis. Recent data regarding epidermal growth factor receptor (EGFR) mutation predicting responsiveness to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), toxicities, and therapeutic efficacy have established the importance of distinguishing squamous cell carcinoma from adenocarcinoma and non-small cell lung carcinoma (NSCLC) not otherwise specified (NOS) in patients with advanced lung cancer.

Approximately 70% of lung cancers are diagnosed and staged by small biopsies or cytology rather than surgical resection specimens, with increasing use of transbronchial needle aspiration (TBNA), endobronchial ultrasound-guided TBNA and esophageal ultrasound-guided needle aspiration. Within the NSCLC group, most pathologists can identify well- or moderately-differentiated squamous cell carcinomas or adenocarcinomas, but specific diagnoses are more difficult with poorly differentiated tumors.

Nevertheless, in small biopsies and/or cytology specimens, upwards of 30% of specimens continue to be diagnosed as NSCLC-NOS. Consistent with most current recommendations, including the recent 2021 WHO paper, it is recommended pathologists “reduce use of the term NSCLC NOS as much as possible and classify tumors according to their specific histologic subtype.

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To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small non-resection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies.

For small biopsies and cytology, we recommend that NSCLC be further classified into a more specific histologic type, such as adenocarcinoma or squamous cell carcinoma, whenever possible (strong recommendation, moderate quality evidence). The terms AIS or MIA should not be used in small biopsies or cytology specimens. If a noninvasive pattern is present in a small biopsy, it should be referred to as lepidic growth The term large cell carcinoma should not be used for diagnosis in small biopsy or cytology specimens and should be restricted to resection specimens where the tumor is thoroughly sampled to exclude a differentiated component.

We recommend discontinuing the use of the term “BAC” We recommend that the term NSCLC-NOS be used as little as possible and we recommend it be applied only when a more specific diagnosis is not possible by morphology and/or special stains (strong recommendation, moderate quality evidence). The above strategy for classification of adenocarcinoma versus other histologies and the terminology should be used in routine diagnosis and future research and clinical trials so that there is uniform classification of disease cohorts in relationship to tumor subtypes.

Travis WD, Brambilla E, Noguchi M, et al. International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society International Multidisciplinary Classification of Lung Adenocarcinoma. Journal of Thoracic Oncology 2011; 6:244-285.

This measure contains one strata defined by a single submission criteria. This measure produces a single performance rate. For purposes of MIPS implementation, this procedure measure is submitted each time a procedure is performed during the performance period. Only one quality data code (QDC) per date of service for a patient is required.