Surgical treatment of breast cancer in Norway 2003-2018. / Kirurgisk behandling av brystkreft i Norge 2003­18.

BACKGROUND: Breast-conserving surgery is recommended in Norway and internationally in cases of early-stage breast cancer. We analysed the surgical methods used for breast-cancer patients by hospital providing treatment, age at the time of diagnosis, detection method and histopathological characteristics of the tumours in the period 2003 to 2018. MATERIAL AND METHOD: Data on women of all ages diagnosed with invasive breast cancer (n = 47 004) were retrieved from the Cancer Registry of Norway's databases. We excluded women with distant metastases at the time of diagnosis (n = 1 773) and those for whom no surgical method was recorded (n = 2 638). The detection method was defined as breast cancer detected by screening, in inter-screening intervals, or outside BreastScreen Norway. The surgical methods chosen were compared by means of descriptive analyses. RESULTS: Slightly over half (23 661 of 42 593, i.e. 55.6 %) of the women in whom breast cancer was detected in the study period underwent breast-conserving surgery. The percentage increased from 1 189/2 423 (49.1 %) in 2003 to 2 070/2 958 (70.0 %) in 2018. There were large differences across hospitals. In the period 2015-2018 we found the highest proportion of breast-conserving surgery, 175/187 (93.6 %) for breast cancer detected by screening to be performed at Ålesund Hospital, and the lowest proportion, 121/351 (34.5 %) among women with breast cancer detected outside BreastScreen Norway, to be performed at Radiumhospitalet. Breast-conserving surgery was used most frequently on women with small tumours without spreading to axillary lymph nodes. INTERPRETATION: We found considerable differences in the surgical methods used across hospitals and for different detection methods.

Radiologic evaluation of lumps in the male breast.

BACKGROUND: Gynecomastia has a typical appearance on mammography, and occurs frequently in men. However, imaging is often performed on men with breast lumps to exclude breast cancer, which only comprises 1% of male breast masses. PURPOSE: To assess whether ultrasound and fine needle aspiration cytology (FNAC) are necessary investigations when mammograms show classical gynecomastia. MATERIAL AND METHODS: We have retrospectively collected data on male patients referred for mammography during the period 2011-2013 (a total of 539 patients). All radiological images were re-read, and descriptions of ultrasound images were reviewed. Clinical information supplied with the original referrals was assessed, along with pathology and cytology reports. RESULTS: Among the 539 male patients who underwent mammography, 483 were also examined with ultrasound, and 335 were further evaluated with FNAC. Mammograms showed gynecomastia in 350 patients, and among these subjects ultrasound was performed in 340 (97%), FNAC in 261 (75%), and core biopsies in four (1%) patients. The diagnosis gynecomastia was unchanged in all patients who underwent FNAC or biopsy. Malignant tumors were found in eight patients, six of which were invasive ductal carcinomas. CONCLUSION: In patients with a classical appearance of gynecomastia on mammography, supplemental ultrasound, FNAC, or biopsy is superfluous and contributes to unnecessary costs.

Long-term follow-up of complex oncoplastic breast-conserving surgery, standard breast conservation and skin-sparing mastectomy in DCIS - a register-based study.

BACKGROUND: Few studies evaluate oncological safety in complex oncoplastic breast-conserving surgery(C-OBCS) for DCIS. It still needs to be defined whether it is equivalent to standard breast conservation(S-BCS) or an alternative to skin-sparing mastectomy(SSM). This study compares local recurrence rates(LR), disease-free survival(DFS) and overall survival (OS) between the three surgical techniques. METHODS: We conducted a retrospective register-based study on LR, DFS and OS of patients operated with S-BCS(n=1388), C-OBCS (n=106) or skin-sparing mastectomy (n=218) for DCIS diagnosed 2007-2020. Data was extracted from the Norwegian Breast Cancer Registry. RESULTS: In the S-BCS, C-OBCS and SSM groups, median age was 60, 58 and 51 years (p<0.001), median size 15, 25, and 40 mm (p<0.001) and median follow-up 55, 48 and 76 months. At ten years, the overall LR was 12.7%, 14.3% for S-BCS, 11.2% for C-OBCS and 6.8% for SSM. Overall DFS at ten years was 82.3%, 80.5% for S-BCS, 82.4% for C-OBCS and 90.4% for SSM. At ten years, the OS was 93.8%, 93.0% in S-BCS, 93.3% in C-OBCS and 96.6% in the SSM group. Weighted Kaplan Meier plots showed that SSM had a significantly higher DFS than S-BCS (p=0.003) and C-OBCS (p=0.029). DFS in C-OBCS versus S-BCS and the difference in OS was not significant (p=0.264). CONCLUSION: SSM had a significantly higher DFS than S-BCS and C-OBCS. The difference in DFS between S-BCS and C-OBCS, and OS between the three groups was not statistically significant. Our study suggests that C-OBCS is a safe alternative to S-BCS and SSM.

Oncological outcomes after simple and skin-sparing mastectomy of ductal carcinoma in situ: A register-based cohort study of 576 Norwegian women.

BACKGROUND: For Ductal Carcinoma in Situ (DCIS), recurrence is shown to be higher after skin-sparing (SSM) versus simple (SM) mastectomy. This study aimed to compare the two groups recurrence rates, disease-free survival (DFS), and overall (OS) survival. METHODS: We conducted a retrospective register-based cohort study of women operated with SSM (n = 338) or SM (n = 238) for DCIS between 2007 and 2017. Data from the Norwegian Breast Cancer Registry was used to estimate recurrences rates, DFS and OS. RESULTS: Mean age was 51 and 61 years in the SSM and SM groups, respectively. Median follow-up time was 77 months for SSM (range: 21-152 months) vs 84 months for SM (range: 7-171 months). After five years of follow-up, the overall recurrence rate (OR) was 2.1%; 3.9% for SSM and 0.9% for SM. After ten years, the rates were 3.0%, 6.2% for SSM and still 0.9% for SM. DFS was after ten years 92.2%; 91.8% for SSM, and 92.4% for SM. OS was 95.0%; 97.5% for SSM and 93.3% for SM at ten years. For SSM, involved margins represented a significant risk for recurrence. CONCLUSION: The recurrence rate was higher in the SSM versus the SM group. Whether the difference is due to the operating procedures or underlying risk factors remains unknown. When stratifying for the difference in age, there was no statistical difference in DFS or OS. Involved margins in the SSM group were associated with an increased risk of recurrence.

Treatment of Ductal Carcinoma in situ: A Register-Based Study of Norwegian Women Diagnosed between 1995 and 2018.

Introduction: The incidence of ductal carcinoma in situ (DCIS) has increased after implementation of mammographic screening. The lesion represents management challenges due to its undetermined growth pattern. We aimed to explore treatment of women aged 48-71 years diagnosed with DCIS between 1995 and 2018, by detection mode and histopathological characteristics. Material and Methods: Data on surgical treatment and radiation therapy (RT) of 4,995 women diagnosed with DCIS were retrieved from the Cancer Registry of Norway. We described the percentage and frequency of breast-conserving treatment (BCT) for participants in BreastScreen Norway (screen-detected) and nonparticipants. We estimated the relative risk (RR) of BCT, using log-binomial regression models. Results: Use of BCT increased from about 40% in 1995 to 85% in 2018. Use of BCT was more common among older than younger women and more commonly used for screen-detected versus tumors detected outside the screening program. Nine out of ten women with tumors ≤10 mm were treated with BCT and two out of ten with tumors >50 mm. RT was given to 89.3% of the women with tumors ≤10 mm, 34.1% of those with tumors classified as van Nuys' grade 1 and <10 mm and 96.0% of the tumors >50 mm. Use of BCT was less common for tumors >50 mm compared to <10 mm (RR adjusted for age, detection mode, van Nuys' grade, and localization: 0.26, 95% CI: 0.19-0.36). Conclusion: BCT was increasingly used among women diagnosed with DCIS in Norway during the period from 1995 to 2018, particularly for screen-detected, small lesions with low van Nuys' grade.