AbstractsMedical & Health Science

Breast cancer is the most frequent cancer among Swedish women and in 2012, 8490 new inva- sive breast cancers were diagnosed. The incidence of in situ breast cancer has markedly in- creased since nationwide mammography screening was introduced in the late 1980s. The in- creasing figures of in situ breast cancer are predominantly attributable to an increased frequency of ductal carcinoma in situ (DCIS). In 2012, 1443 in situ breast cancers were diagnosed in Swe- den, which is approximately 15% of all diagnosed breast cancers. The main aims of the first two papers were to study the long-term HRQOL after different types of surgical treatment in women with DCIS (paper I) and to study the risk of developing a new in situ or invasive breast cancer after a first in situ cancer in women with and without a family his- tory for breast cancer (paper II). Since the 1980s, breast-conserving surgery for DCIS has been recommended whenever feasible. Several randomised trials have shown a decreased rate of ipsi- lateral DCIS or invasive breast cancer recurrence through the addition of adjuvant radiotherapy. Mastectomy is still recommended for women with either multifocal DCIS, and/or unfavourable proportion between tumour size and breast volume. For these women an immediate breast re- construction (IBR) is an alternative to maintain a breast contour. As surgery is the primary treatment for this disease, it is essential to increase current understanding of its long-term con- sequences. In paper I, 162 women treated for DCIS with breast-conserving surgery with or without postoperative radiotherapy, or with mastectomy and IBR, had a satisfactory long-term HRQOL. However, body image appeared to be affected in women after mastectomy and IBR. Using the population-based Swedish Multi-Generation and Cancer Registers we identified 8,111 women (paper II) diagnosed with in situ breast cancer between 1980 and 2004. The risk of a subsequent invasive breast cancer was increased more than fourfold [SIR 4.55 (95% CI 4.23- 4.88)] among women with in situ breast cancer as compared to women in the general population and the risk for a contralateral in situ breast cancer was almost sixteenfold increased [SIR 15.98(95% CI, 13.23-19.14)]. Having a family history for breast cancer increased the risk for contralateral invasive breast cancer by almost 50 % [incidence rate ratio 1.47 (95% CI 1.05- 2.05)]. The risk for a subsequent invasive breast cancer, as well as mortality was substantially higher in younger women, which should be taken into account when planning their treatment and follow-up. The main aims of paper III and IV were to evaluate the impact of axillary surgery on arm lym- phoedema and long-term HRQOL. Axillary lymph node dissection (ALND) was the standard surgical procedure for staging well into the 1990s, when it was replaced by the sentinel lymph node biopsy (SLNB), in patients with preoperatively no signs of axillary metastases. In a multi- centre study, including 557 women, we showed that SLNB alone is associated with a minimal…