Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA.
Division of Pulmonary, Allergy and Critical Care, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA.
Clin Lung Cancer. 2022 Nov;23(7):e453-e459. doi: 10.1016/j.cllc.2022.06.006. Epub 2022 Jul 1.
Pulmonary carcinoid tumor (PCT) is a rare neuroendocrine lung neoplasm comprising approximately 2% of lung cancer diagnoses. It is classified as either localized low-grade (typical) or intermediate-grade (atypical) subtypes. PCT is known clinically to be a slow-growing cancer, however few studies have established its true growth rate when followed over time by computed tomography (CT). Therefore, we sought to determine the volume doubling time for PCTs as visualized on CT imaging.
We conducted a retrospective analysis of all PCTs treated at our institution between 2006 and 2020. Nodule dimensions were measured using a Picture Archiving and Communication System or retrieved from radiology reports. Volume doubling time was calculated using the Schwartz formula for PCTs followed by successive CT scans during radiographic surveillance. Consistent with Fleischner Society guidelines, tumors were considered to have demonstrated definitive growth by CT only when the interval change in tumor diameter was greater than or equal to 2 mm.
The median volume doubling time of 13 typical PCTs was 977 days, or 2.7 years. Five atypical PCTs were followed longitudinally, with a median doubling time of 327 days, or 0.9 years.
Typical pulmonary carcinoid features a remarkably slow growth rate as compared to more common lung cancers. Our analysis of atypical pulmonary carcinoid included too few cases to offer definitive conclusions. It is conceivable that clinicians following current nodule surveillance guidelines may mistake incidentally detected typical carcinoids for benign non-growing lesions when followed for less than 2 years in low-risk patients.
肺类癌肿瘤（PCT）是一种罕见的神经内分泌肺肿瘤，约占肺癌诊断的 2%。它可分为局限性低级别（典型）或中级别（非典型）亚型。临床上已知 PCT 是一种生长缓慢的癌症，但很少有研究在通过计算机断层扫描（CT）随时间对其进行随访时确定其真实生长速度。因此，我们试图确定 CT 成像上观察到的 PCT 的倍增时间。
我们对 2006 年至 2020 年在我们机构治疗的所有 PCT 进行了回顾性分析。使用图片存档和通信系统或从放射学报告中测量结节尺寸。使用 Schwartz 公式计算倍增时间，用于对连续 CT 扫描进行 PCT 随访期间的放射性监测。根据 Fleischner 学会的指南，只有当肿瘤直径的间隔变化大于或等于 2 毫米时，才能通过 CT 确定肿瘤具有明确的生长。
13 例典型 PCT 的中位倍增时间为 977 天，即 2.7 年。5 例非典型 PCT 进行了纵向随访，中位倍增时间为 327 天，即 0.9 年。
与更常见的肺癌相比，典型肺类癌的生长速度非常缓慢。我们对非典型肺类癌的分析包括的病例太少，无法得出明确的结论。可以想象，遵循当前结节监测指南的临床医生在低危患者中随访不到 2 年时，可能会将偶然发现的典型类癌误认为是良性非生长病变。
