TY - JOUR
T1 - Risk factors for cancers of unknown primary site: Results from the prospective EPIC cohort
AU - Kaaks, Rudolf
AU - Sookthai, Disorn
AU - Hemminki, Kari
AU - Kraemer, Alwin
AU - Boeing, Heiner
AU - Wirfält, Elisabet
AU - Weiderpass, Elisabete
AU - Overvad, Kim
AU - Tjonneland, Anne
AU - Olsen, Anja
AU - Peeters, Petra H.
AU - Bueno-de-Mesquita, H. B. (As)
AU - Panico, Salvatore
AU - Pala, Valeria
AU - Vineis, Paolo
AU - Ramon Quiros, J.
AU - Ardanaz, Eva
AU - Sanchez, Maria-Jose
AU - Chirlaque, Maria-Dolores
AU - Larranaga, Nerea
AU - Brennan, Paul
AU - Trichopoulos, Dimitrios
AU - Trichopoulou, Antonia
AU - Lagiou, Pagona
AU - Hallmans, Goeran
AU - Khaw, Kay-Tee
AU - Key, Timothy J.
AU - Riboli, Elio
AU - Canzian, Federico
PY - 2014
Y1 - 2014
N2 - Cancer of unknown primary site (CUP) may be called an orphan disease, as it is diagnosed when metastases are detected while the primary tumor typically remains undetected, and because little research has been done on its primary causes. So far, few epidemiological studies, if any, have addressed possible risk factors for CUP. We analyzed data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (N=476,940). During prospective follow-up, a total of 651 cases of incident cases of CUP were detected (ICD-O-2 code C809). Proportional hazards models were conducted to examine the associations of lifetime history of smoking habits, alcohol consumption, levels of education and anthropometric indices of adiposity with risk of being diagnosed with CUP. Risk of being diagnosed with CUP was strongly related to smoking, with a relative risk of 3.66 [95% C.I., 2.24-5.97] for current, heavy smokers (26+ cigarettes/day) compared to never smokers (adjusted for alcohol consumption, body mass index, waist circumference and level of education) and a relative risk of 5.12 [3.09-8.47] for cases with CUP who died within 12 months. For alcohol consumption and level of education, weaker associations were observed but attenuated and no longer statistically significant after adjusting for smoking and indices of obesity. Finally, risk of CUP was increased by approximately 30 per cent for subjects in the highest versus lowest quartiles of waist circumference. Our analyses provide further documentation, in addition to autopsy studies, that a substantial proportion of cancers of unknown primary site may have their origin in smoking-related tumors, in particular. What's new? When cancer appears as metastatic disease but no primary tumor can be observed, it's called cancer of unknown primary site. Little is known about the risk factors for this type of cancer. This study analyzed data from a European cohort and discovered a strong association between smoking and these cancers. Other risk factors they identified were drinking alcohol and being fat. This is the first epidemiological study of these type of cancers, and it strengthens the observations from autopsy studies that many of these cancers of unknown primary site stem from smoking-related tumors.
AB - Cancer of unknown primary site (CUP) may be called an orphan disease, as it is diagnosed when metastases are detected while the primary tumor typically remains undetected, and because little research has been done on its primary causes. So far, few epidemiological studies, if any, have addressed possible risk factors for CUP. We analyzed data from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (N=476,940). During prospective follow-up, a total of 651 cases of incident cases of CUP were detected (ICD-O-2 code C809). Proportional hazards models were conducted to examine the associations of lifetime history of smoking habits, alcohol consumption, levels of education and anthropometric indices of adiposity with risk of being diagnosed with CUP. Risk of being diagnosed with CUP was strongly related to smoking, with a relative risk of 3.66 [95% C.I., 2.24-5.97] for current, heavy smokers (26+ cigarettes/day) compared to never smokers (adjusted for alcohol consumption, body mass index, waist circumference and level of education) and a relative risk of 5.12 [3.09-8.47] for cases with CUP who died within 12 months. For alcohol consumption and level of education, weaker associations were observed but attenuated and no longer statistically significant after adjusting for smoking and indices of obesity. Finally, risk of CUP was increased by approximately 30 per cent for subjects in the highest versus lowest quartiles of waist circumference. Our analyses provide further documentation, in addition to autopsy studies, that a substantial proportion of cancers of unknown primary site may have their origin in smoking-related tumors, in particular. What's new? When cancer appears as metastatic disease but no primary tumor can be observed, it's called cancer of unknown primary site. Little is known about the risk factors for this type of cancer. This study analyzed data from a European cohort and discovered a strong association between smoking and these cancers. Other risk factors they identified were drinking alcohol and being fat. This is the first epidemiological study of these type of cancers, and it strengthens the observations from autopsy studies that many of these cancers of unknown primary site stem from smoking-related tumors.
KW - cancer of unknown primary site (CUP)
KW - prospective cohort study
KW - smoking
KW - alcohol
KW - obesity
KW - waist circumference
U2 - 10.1002/ijc.28874
DO - 10.1002/ijc.28874
M3 - Article
C2 - 24692151
SN - 0020-7136
VL - 135
SP - 2475
EP - 2481
JO - International Journal of Cancer
JF - International Journal of Cancer
IS - 10
ER -
