Page 83 - New epidemiological and PSMA-expression based paradigms in salivary gland tumors

Risk of breast cancer after a salivary gland tumor in the Netherlands
did not vary with age at SGC diagnosis (SIR <50 years: 1.54, 95% CI 0.79-2.68; SIR 50-69 years: 1.69, 95% CI 1.10-2.48; SIR ≥70 years: 1.48, 95% CI 0.81-2.49, p-heterogeneity=0.91) nor did they change with follow-up duration (SIR <10 years: 1.76, 95% CI 1.28-2.38; SIR 10-19 years: 0.92, 95% CI 0.37-1.89; SIR ≥20 years: 2.70, 95% CI 0.56-7.90, p-heterogeneity=0.19) or histological SGC subtype (table 3). For SGPA patients, BC incidence did neither vary with age at SGPA diagnosis nor with follow-up duration. A sensitivity analysis, showed similar risks after exclusion of synchronous BC (n=4), defined as all BC diagnosed < 3 months after the salivary gland tumor diagnosis; the SIR was 1.57; (95% CI 1.14-2.09) for SGC and 1.33 (95% CI 1.04-1.64) for SGPA, respectively.
In the SGC-cohort, the absolute excess risk (AER) of DCIS and invasive BC combined was 17.7, in other words 17.7 excess BC for every 1,000 women, each followed for 10 years. In the SGPA-cohort the AER was 12.8 per 10,000 person-years.
Table 1. Population characteristics of the salivary gland carcinoma (SGC) or salivary gland pleomorphic adenoma (SGPA) with and without subsequent breast cancer (BC).
5
SGC
Subseq. BC No subseq. BC BC (n=52) (n=1,515) (n=74)
SGPA
no BC (n=2,009)
48 (37-63)
321 746 942
Age at diagnosis, yrs† (IQR) Year of salivary tumor diagnose
1989-1994 1995-2004 2005-2013
Histology SG tumor*, N(%)
Adenoid cystic ca. Muco-epidermoid ca.
Acinic cell ca.
Ca. ex Pleomorphic Adenoma Adenoca., NOS
Squamous cell ca. Myo-epithelial ca. Salivary duct ca.
Other salivary gland ca. Pleomorphic adenoma
Stage, N (%)
I II III IV
57 (49-69)
13 25 14
9 (17.3) 9 (17.3) 9 (17.3) 6 (11.5) 7 (13.5) 2 (3.8) 4 (7.7) 1 (1.9) 5 (9.6)
15 (28.8) 10 (19.2) 4 (7.7)
5 (9.6)
63 (47-75)
282 557 676
305 (20.1) 227 (15) 263 (17.4) 106 (7) 204 (13.5) 95 (6.3) 95 (6.3) 29 (1.9) 190 (12.5)
436 (28.8) 226 (14.9) 163 (10.8) 328 (21.7)
50 (42-66)
22 37 15
74 (100) NA
2,009 (100) NA
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