Sample characteristics
All the 1320 patients with sarcomas were matched for the 1320 controls from the National Health and Nutrition Examination Survey conducted by the Japanese Ministry of Health, Labour and Welfare in 2014 [40]. A total of 2640 subjects were analyzed after PSM. The characteristics of the 1320 sarcoma patients were as follows: smoking habit, n=400 (30%); drinking habit, n=303 (23%); obesity, n=258 (20%); DM, n=70 (5%); hypertension, n=183 (14%); and dyslipidemia, n=79 (6%). The characteristics of the 1320 controls were as follow: smoking habit, n=242 (18%); drinking habit, n=276 (21%); obesity, n=229 (17%); DM, n=48 (4%); hypertension, n=154 (12%); and dyslipidemia, n=89 (7%) (Table 1).
In total, 8% (108/1320) of patients with sarcoma in the bone and soft tissue had a personal cancer history. On the other hand, patients with sarcoma in the bone and soft tissue in total had family history of cancers as follows: up to first-degree, n=367 (28%); up to second-degree, n=651 (49%); and up to third-degree relatives, n=730 (55%) (Table 2).
Relationship between life-style /personal cancer history /family history and sarcoma
In the multivariate analysis, a smoking habit increased sarcoma with an OR of 2.03, (95% confidence interval [CI] 1.66-2.48, p<0.001). Alcohol drinking habit, obesity, hypertension, and dyslipidemia were not significantly associated with the development of bone and soft tissue sarcoma (Table 1).
The smoking rate was 400/1320 (%) in sarcoma patients, 61/274 (22%) in patients with malignant bone tumors, and 339/1046 (32%) in patients with malignant soft tissue tumors, respectively (Table 3).
Among high-grade malignancies in adults ≥20 years old (n=952), excluding low-grade and intermediate malignant tumors (giant cell tumor of bone, atypical lipomatous tumor, desmoid-type fibromatosis, etc.), the OR of a smoking habit in high-grade sarcoma patients was 2.14 (95% CI 1.70-2.69, p<0.001), and that in patients with high-grade bone sarcoma was 1.55 (95% CI 0.94-2.56, p=0.09) and that in patients with high-grade soft tissue sarcoma was 2.45 (95% CI 1.88-3.20, p<0.001), according to the multivariate analysis after PSM (Table 4).
The rate of a personal cancer history in malignant bone tumor patients was 5% (14/274). The rates of malignant bone tumor patients with a family history of cancer up to the first-, second-, and third-degree relatives were 20% (56/274), 46% (127/274), and 52% (142/274), respectively. The rate of a personal cancer history in malignant soft tissue tumor patients was 9% (94/1046). The rates of the malignant soft tissue tumor patients with a family history of cancer up to the first-, second-, and third-degree relatives were 30% (311/1046), 50% (524/1046), and 55% (578/1046), respectively (Table 5).
Distribution of life-style /personal cancer history /family history in respective sarcoma histology subtypes
In terms of the histological subtypes among adults ≥20 years old with high-grade soft tissue sarcoma, the smoking rates in patients with undifferentiated pleomorphic sarcoma (UPS) and liposarcoma were higher than those in controls: 43% (75/175) vs. 20% (35/175), and 44% (65 /147) vs. 19% (35/147), respectively. The ORs were 3.00 (95% CI: 1.76-5.11, p<0.001) and 2.56 (95% CI: 1.47-4.44, p<0.001), respectively (Table 4).
The rate of no significant personal cancer history was >10% in patients with any type of bone sarcoma. Among cases of soft tissue sarcoma, patients with angiosarcoma (38%; 6/22) and UPS (17%; 31/180) tended to have a personal history of another cancer. The most common types of historical cancer in these patients were breast cancer (16%; 15/94), colorectal cancer (11%; 10/94), and lung cancer (10%; 9/94) (Table 6A).
In bone sarcoma, 41% (7/17) of patients with chordoma had a first-degree relative family history of cancer. In soft tissue sarcoma, 52% (13/25) of the patients with malignant peripheral nerve sheath tumor (MPNST), and 46% (26/57) of the patients with leiomyosarcoma, 42% (5/12) of the patients with extraskeletal myxoid chondrosarcoma (EMC), and 39% (21/54) of the patients with synovial sarcoma, had a family history of cancer up to the first-degree relatives, although the numbers of each histological subtype were comparatively small due to their rarity (Table 5). The common types of family cancer were gastric cancer, lung cancer and colorectal cancer in both bone and soft tissue sarcoma patients. Gastric cancer was most commonly associated with 30% (17/56) of family cancers up to the first-degree relatives of bone sarcoma patients, and 34% (107/311) of family cancers up to the first-degree relatives of soft tissue sarcoma patients. Lung cancer and colorectal cancer were also highly associated with 18% (10/56) and 20% (11/56) of family cancers up to the first-degree relatives of bone sarcoma patients, and 23% (71/311) and 20% (62/311) of family cancers up to the first-degree relatives of soft tissue sarcoma patients, respectively (Table 6B).