Abstract
Converging evidence indicates that women with pregnancy-associated breast cancer (PABC) have increased mortality compared to women with breast cancer not diagnosed near pregnancy (non-PABC). Our aim was to investigate if the stage distribution differs between PABC and non-PABC and if stage at diagnosis can explain the poorer prognosis observed among women with PABC. We identified 3,282 breast cancers in women aged 15–44 years at diagnosis for whom staging data (tumor size, nodal involvement, metastasis) were available in the Swedish Cancer Register between 2002 and 2009. Information on reproductive history and vital status was obtained from the Multi-Generation Register and the Cause of Death Register. PABC was defined as breast cancers diagnosed during pregnancy and up to 2 years after delivery (n = 317). Non-PABC was defined as cases diagnosed before pregnancy or more than 2 years postpartum. Stage distributions were compared between PABC and non-PABC, and mortality rates were modeled using Cox regression. Compared to women with non-PABC, the mortality was almost 50 % higher in women with PABC [unadjusted hazard ratio (HR) 1.47 (95 % CI 1.04–2.08)], a difference which was reduced after adjustment for age and calendar year of diagnosis [HR 1.27 (95 % CI 0.88–1.83)]. Although advanced stage of breast cancer at diagnosis was more common among PABC than among non-PABC, further adjustment for stage only slightly reduced the HR [1.22 (95 % CI 0.84–1.78)]. The difference in mortality between PABC and non-PABC was more pronounced among women above 35 years and among women with PABC diagnosed within 1 year postpartum. Age, rather than stage at diagnosis, appears to act as the principal driver of the increased mortality observed in women with PABC. However, these findings do not preclude an untoward influence on mortality by pregnancy-associated factors affecting tumor aggressiveness and progression.
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Callihan EB, Gao D, Jindal S, Lyons TR, Manthey E, Edgerton S, Urquhart A, Schedin P, Borges VF (2013) Postpartum diagnosis demonstrates a high risk for metastasis and merits an expanded definition of pregnancy-associated breast cancer. Breast cancer research and treatment. doi:10.1007/s10549-013-2437-x
Murphy CG, Mallam D, Stein S, Patil S, Howard J, Sklarin N, Hudis CA, Gemignani ML, Seidman AD (2011) Current or recent pregnancy is associated with adverse pathologic features but not impaired survival in early breast cancer. Cancer. doi:10.1002/cncr.26654
Moreira WB, Brandao EC, Soares AN, Lucena CE, Antunes CM (2010) Prognosis for patients diagnosed with pregnancy-associated breast cancer: a paired case-control study. Sao Paulo Med J 128(3):119–124
Beadle BM, Woodward WA, Middleton LP, Tereffe W, Strom EA, Litton JK, Meric-Bernstam F, Theriault RL, Buchholz TA, Perkins GH (2009) The impact of pregnancy on breast cancer outcomes in women < or =35 years. Cancer 115(6):1174–1184. doi:10.1002/cncr.24165
Stensheim H, Moller B, van Dijk T, Fossa SD (2009) Cause-specific survival for women diagnosed with cancer during pregnancy or lactation: a registry-based cohort study. J Clin Oncol 27(1):45–51
Rodriguez AO, Chew H, Cress R, Xing G, McElvy S, Danielsen B, Smith L (2008) Evidence of poorer survival in pregnancy-associated breast cancer. Obstet Gynecol 112(1):71–78. doi:10.1097/AOG.0b013e31817c4ebc
Azim HA Jr., Santoro L, Russell-Edu W, Pentheroudakis G, Pavlidis N, Peccatori FA (2012) Prognosis of pregnancy-associated breast cancer: a meta-analysis of 30 studies. Cancer Treat Rev. doi:10.1016/j.ctrv.2012.06.004
Schedin P (2006) Pregnancy-associated breast cancer and metastasis. Nat Rev Cancer 6(4):281–291
Woo JC, Yu T, Hurd TC (2003) Breast cancer in pregnancy: a literature review. Arch Surg 138(1):91–98 (discussion 99)
Leslie KK, Lange CA (2005) Breast cancer and pregnancy. Obstet Gynecol Clin North Am 32(4):547–558
Lambe M, Ekbom A (1995) Cancers coinciding with childbearing: delayed diagnosis during pregnancy? BMJ 311(7020):1607–1608
Petrek JA (1994) Breast cancer during pregnancy. Cancer 74(1 Suppl):518–527
Ali SA, Gupta S, Sehgal R, Vogel V (2012) Survival outcomes in pregnancy associated breast cancer: a retrospective case control study. Breast J 18(2):139–144. doi:10.1111/j.1524-4741.2011.01201.x
Azim HA Jr, Botteri E, Renne G, Dell’orto P, Rotmensz N, Gentilini O, Sangalli C, Pruneri G, Di Nubila B, Locatelli M, Sotiriou C, Piccart M, Goldhirsch A, Viale G, Peccatori FA (2012) The biological features and prognosis of breast cancer diagnosed during pregnancy: a case-control study. Acta Oncol 51(5):653–661. doi:10.3109/0284186X.2011.636069
Barlow L, Westergren K, Holmberg L, Talback M (1998) The completeness of the Swedish cancer register: a sample survey for year. Acta Oncol 48(1):27–33. doi:10.1080/02841860802247664
Sobin LH, Wittekind C (2002) TNM classification of malignant tumors, 6th edn. Wiley, Hoboken, New Jersey, USA
StataCorp (2011) Stata statistical software: release 12. StataCorp LP, College Station, TX, USA
Borges VF, Schedin PJ (2011) Pregnancy-associated breast cancer: an entity needing refinement of the definition. Cancer. doi:10.1002/cncr.26643
Mathelin C, Annane K, Treisser A, Chenard MP, Tomasetto C, Bellocq JP, Rio MC (2008) Pregnancy and post-partum breast cancer: a prospective study. Anticancer Res 28(4C):2447–2452
Ries LAG, Young JL, Keel GE, Eisner MP, Lin YD, Horner MJ (2007) SEER survival monograph. Cancer survival among adults: U.S. SEER program, 1988–2001, patient and tumor characteristics. National Cancer Institute, SEER Program, NIH Pub. No. 07–6215, Bethesda, MD
Yankaskas BC (2005) Epidemiology of breast cancer in young women. Breast Dis 23:3–8
Johansson AL, Andersson TM, Hsieh CC, Cnattingius S, Lambe M (2011) Increased mortality in women with breast cancer detected during pregnancy and different periods postpartum. Cancer Epidemiol Biomark Prev 20(9):1865–1872. doi:10.1158/1055-9965.EPI-11-0515
Statistics Sweden (2012) Statistics database (Statistikdatabasen). www.scb.se. Accessed 20 Dec 2012
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This work was supported by a grant from Susan G Komen for the cure (Grant Number KG 100116).
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Johansson, A.L.V., Andersson, T.ML., Hsieh, CC. et al. Stage at diagnosis and mortality in women with pregnancy-associated breast cancer (PABC). Breast Cancer Res Treat 139, 183–192 (2013). https://doi.org/10.1007/s10549-013-2522-1
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DOI: https://doi.org/10.1007/s10549-013-2522-1