Characteristics of 1270 Chinese Sibling Pairs with Cancer

Abstract

16 Background: Previous research found that the cancer history of an individual’s sibling may 17 be a better indicator than that of the parents. We aim to provide recommendations for early 18 screening for individuals whose sibling had been diagnosed with cancer. 19 Methods: During the physical examination in Cancer Hospital, Chinese Academy of Medical 20 Sciences, 43,300 people were asked if they have at least two siblings who developed cancer. 21 Eligible participants were asked to fill out a survey and participate in interviews. 22 Results: A total of 1270 sibling-pairs from 766 families developed cancer, including 367 pairs 23 of brothers (Bro-pairs), 368 pairs of sisters (Sis-pairs), and 535 pairs of brother-and-sister 24 (BroSis-pairs). The mean ages at diagnosis of cancer for the three groups were from 58 to 62 25 years. More than half of Bro-pairs (55.3%) or Sis-pairs (51.1%) had cancer from the same 26 systemic origin, and more than a quarter of Bro-pairs (28.1%) and Sis-pairs (37.2%) developed 27 the same type of cancer. However, only 36.0% of BroSis-pairs developed cancers from the 28 same systemic origin, and 18.9% developed the same type of cancer. In Bro-pairs and BroSis29 pairs, lung cancer and digestive system cancer were the most common cancers, while in Sis30 pairs, breast cancer, lung cancer, cervical cancer, liver cancer and thyroid cancer the most 31 common ones. 32 Conclusions: If an individual’s sibling is diagnosed with cancer, the individual should be 33 screened as soon as possible, especially for lung cancer and digestive system cancers for both 34 sexes. For sisters, breast cancer, cervical cancer and thyroid cancer should be screened early. 35 Additionally, genetic services are essential for individuals who have siblings with cancer. 36