Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia;
Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia.
J Nucl Med. 2024 Oct 1;65(10):1557-1563. doi: 10.2967/jnumed.123.267274.
Cancer of unknown primary (CUP) represents a heterogeneous group of metastatic tumors for which standardized diagnostic work-up fails to identify the primary site. We aimed to describe the Peter MacCallum Cancer Centre experience with F-FDG PET/CT in extracervical CUP with respect to detection of a primary site and its impact on management. A secondary aim was to compare overall survival (OS) in patients with and without a detected primary site. CUP patients treated between 2014 and 2020 were identified from medical oncology clinics and F-FDG PET/CT records. Information collated from electronic medical records included the suspected primary site and treatment details before and after F-FDG PET/CT. Clinicopathologic details and genomic analysis were used to determine the clinically suspected primary site and compared against 2 independent masked reads of F-FDG PET/CT images by nuclear medicine specialists to determine sensitivity, specificity, accuracy, and the rate of detection of the primary site. We identified 147 patients, 65% of whom had undergone molecular profiling. The median age at diagnosis was 61 y (range, 20-84 y), and the median follow-up time was 74 mo (range, 26-83 mo). Eighty-two percent were classified as having an unfavorable CUP subtype as per international guidelines.F-FDG PET/CT demonstrated a primary site detection rate of 41%, resulted in a change in management in 22%, and identified previously occult disease sites in 37%. Median OS was 16.8 mo for all patients and 104.7 and 12.1 mo for favorable and unfavorable CUP subtypes, respectively ( < 0.0001). Median OS in CUP patients when using F-FDG PET/CT, clinicopathologic, and genomic information was 19.8 and 8.5 mo when a primary site was detected and not detected, respectively ( = 0.016). Multivariable analysis of survival adjusted for age and sex remained significant for identification of a potential primary site ( < 0.001), a favorable CUP ( < 0.001), and an Eastern Cooperative Oncology Group status of 1 or less ( < 0.001). F-FDG PET/CT plays a complementary role in CUP diagnostic work-up and was able to determine the likely primary site in 41% of cases. OS is improved with primary site identification, demonstrating the value of access to diagnostic F-FDG PET/CT for CUP patients.
原发灶不明的癌症（CUP）代表一组异质性的转移性肿瘤，其标准化的诊断检查未能确定原发灶。我们旨在描述彼得·麦卡伦癌症中心（Peter MacCallum Cancer Centre）在颈椎外 CUP 中使用 F-FDG PET/CT 的经验，包括检测原发灶及其对治疗的影响。次要目标是比较有和无检测到原发灶的患者的总生存（OS）。
从肿瘤内科诊所和 F-FDG PET/CT 记录中确定了 2014 年至 2020 年间治疗的 CUP 患者。从电子病历中收集的信息包括疑似原发灶和 F-FDG PET/CT 前后的治疗细节。临床病理细节和基因组分析用于确定临床疑似原发灶，并与核医学专家对 2 份独立的 F-FDG PET/CT 图像进行的盲法阅读进行比较，以确定灵敏度、特异性、准确性和原发灶的检出率。
我们共确定了 147 名患者，其中 65%的患者进行了分子谱分析。诊断时的中位年龄为 61 岁（范围 20-84 岁），中位随访时间为 74 个月（范围 26-83 个月）。根据国际指南，82%的患者被归类为具有不利的 CUP 亚型。
F-FDG PET/CT 的原发灶检出率为 41%，导致治疗方案改变的比例为 22%，并发现了 37%以前隐匿的疾病部位。所有患者的中位 OS 为 16.8 个月，有利和不利的 CUP 亚型分别为 104.7 和 12.1 个月（<0.0001）。在使用 F-FDG PET/CT、临床病理和基因组信息的 CUP 患者中，当检测到和未检测到原发灶时，中位 OS 分别为 19.8 和 8.5 个月（=0.016）。多变量生存分析调整年龄和性别后，仍显示识别潜在原发灶（<0.001）、有利的 CUP（<0.001）和东部肿瘤协作组（Eastern Cooperative Oncology Group，ECOG）状态为 1 或更低（<0.001）具有显著意义。
F-FDG PET/CT 在 CUP 的诊断评估中发挥了补充作用，能够在 41%的病例中确定可能的原发灶。确定原发灶可改善 OS，表明 CUP 患者获得诊断用 F-FDG PET/CT 的价值。
