Familial pancreatic cancer (FPC) is a rare hereditary tumor entity with broad phenotypic heterogeneity, including colorectal carcinoma (CRC) in some families. The underlying factors for this co-occurrence are still not well evaluated. FPC families in the National Case Collection of Familial Pancreatic Cancer with an additional occurrence of CRC were analyzed regarding the phenotype, genotype and recommendation for a clinical screening program. The total cohort of 272 FPC families included 30 (11%) families with at least one CRC case. The proportion of affected family members with PDAC was 16.1% (73/451) compared to 9.3% of family members with CRC (42/451, p < 0.01). Females were affected with PDAC in 49% (36/73) and CRC in 38% (16/42). The median age of PDAC was 63 compared to 66 years in CRC, whereas 8 (26.6%) of families had an early onset of PDAC and 2 (6.7%) of CRC. Seventeen families had 2 or more affected generations with PDAC and 6 families with CRC. Eleven (9.6%) of affected patients had both PDAC and CRC. Potentially causative germline mutations (2 ATM, 1 CDKN2a, 1 MLH1, 1 PALB2) were detected in 5 of 18 (27.7%) analyzed cases. These findings provide a step forward to include the phenotypic and genotypic characteristics of FPC-CRC families for the genetic counseling and management of these families. Nevertheless, results need to be verified in a larger patient cohort beforehand.

家族性胰腺癌（FPC）是一种罕见的遗传性肿瘤实体，具有广泛的表型异质性，包括一些家族中的结直肠癌（CRC）。这种同时发生的潜在因素仍未得到很好的评估。对国家家族性胰腺癌病例集中额外发生 CRC 的 FPC 家族进行了表型、基因型和临床筛查计划建议的分析。总共 272 个 FPC 家庭队列中，有 30 个（11%）家庭至少患有 1 例 CRC 病例。患有 PDAC 的受影响家庭成员的比例为 16.1% (73/451)，而患有 CRC 的家庭成员的比例为 9.3% (42/451，p < 0.01)。女性中 49% (36/73) 患有 PDAC，38% (16/42) 患有 CRC。PDAC 的中位年龄为 63 岁，而 CRC 的中位年龄为 66 岁，而 CRC 的中位年龄为 8 岁（26 岁）。6%）的家庭患有 PDAC 早期发病，2 个家庭（6.7%）患有 CRC。17 个家庭有 2 代或更多代患有 PDAC，6 个家庭患有 CRC。11 名 (9.6%) 受影响的患者同时患有 PDAC 和 CRC。潜在致病性种系突变 (2在 18 例分析病例中，有 5 例 (27.7%) 检测到ATM、1 个CDKN2a、1 个MLH1、1个PALB2 。这些发现为纳入 FPC-CRC 家族的表型和基因型特征，为这些家族的遗传咨询和管理迈出了一步。然而，结果需要事先在更大的患者队列中进行验证。