Magnetic resonance imaging before breast cancer surgery: results of an observational multicenter international prospective analysis (MIPA)

Objectives Preoperative breast magnetic resonance imaging (MRI) can inform surgical planning but might cause overtreatment by increasing the mastectomy rate. The Multicenter International Prospective Analysis (MIPA) study investigated this controversial issue. Methods This observational study enrolled women aged 18–80 years with biopsy-proven breast cancer, who underwent MRI in addition to conventional imaging (mammography and/or breast ultrasonography) or conventional imaging alone before surgery as routine practice at 27 centers. Exclusion criteria included planned neoadjuvant therapy, pregnancy, personal history of any cancer, and distant metastases. Results Of 5896 analyzed patients, 2763 (46.9%) had conventional imaging only (noMRI group), and 3133 (53.1%) underwent MRI that was performed for diagnosis, screening, or unknown purposes in 692/3133 women (22.1%), with preoperative intent in 2441/3133 women (77.9%, MRI group). Patients in the MRI group were younger, had denser breasts, more cancers ≥ 20 mm, and a higher rate of invasive lobular histology than patients who underwent conventional imaging alone (p < 0.001 for all comparisons). Mastectomy was planned based on conventional imaging in 22.4% (MRI group) versus 14.4% (noMRI group) (p < 0.001). The additional planned mastectomy rate in the MRI group was 11.3%. The overall performed first- plus second-line mastectomy rate was 36.3% (MRI group) versus 18.0% (noMRI group) (p < 0.001). In women receiving conserving surgery, MRI group had a significantly lower reoperation rate (8.5% versus 11.7%, p < 0.001). Conclusions Clinicians requested breast MRI for women with a higher a priori probability of receiving mastectomy. MRI was associated with 11.3% more mastectomies, and with 3.2% fewer reoperations in the breast conservation subgroup. Key Points • In 19% of patients of the MIPA study, breast MRI was performed for screening or diagnostic purposes. • The current patient selection to preoperative breast MRI implies an 11% increase in mastectomies, counterbalanced by a 3% reduction of the reoperation rate. • Data from the MIPA study can support discussion in tumor boards when preoperative MRI is under consideration and should be shared with patients to achieve informed decision-making.

1573 Can the Technique of Local Perforator Flaps Reduce the Volume of Mastectomies?

Aim National reported mastectomy rate varies from 25% - 45%. Also, when a reduction therapeutic mammoplasty is needed, symmetrisation of the contralateral side will follow. Can the “relative new” technique of local perforator flaps, reduce the volume of mastectomies and contralateral surgery in a District General Hospital? Method Retrospective review of yearly breast cancer treatment operations in Ipswich Hospital. Results 332 surgical operations performed for breast cancer. 79/332 (23,7%) had mastectomy, 54/332 (16,26%) had therapeutic mammoplasty with symmetrisation contralateral surgery, 32/332 (9,63%) had local perforator Flap Surgery. From the perforator flap operations, 23/32 (23/332: 6,92%) would have mastectomy (+/- reconstruction) and 9/32 (11/332: 2,71%) would have therapeutic reduction mammoplasty with contralateral symmetrisation surgery if this surgical option was not available. 0/32 (0,00%) of the local perforator flaps failed. Conclusions Local perforator flaps have resulted in 6,92% reduction in mastectomy rate (also eliminating the possible need for reconstructions). This was in small volume breasts and lower pole carcinomas and 2,71% reduction in symmetrisation surgery. This reduction also reduces the cost of cancer treatment without compromising oncological outcome or patient satisfaction.

Features of Breast Cancer in Iranian-born Migrant Women Treated in Australia

Background: While there is much information available about breast cancer in Australia overall, less is known about breast cancer in immigrant women and specifically Iranian-born women. Understanding this group is important to provide appropriate screening, treatment and support interventions. The aim of this study was to describe breast cancer presentation, tumour and treatment characteristics in Iranian-born women in Australia. Methods: Women were eligible for this retrospective audit if treated for breast malignancy with country of birth recorded. Demographic, tumour and surgical data were extracted and analysed. Data for Iranian-born women were compared to data for Australian-born (comparison group 1) and women born in countries other than Australia or Iran (comparison group 2, referred to as ‘other’). Results: 2086 women were eligible: Iranian-born n=27, Australian-born n=894 and Other n=1165. Iranian-born women were younger, mean age of 53.9 (five years younger in overall mean, SD 11.98, F=3.171, p=0.042). Iranian-born women were significantly less likely to present with a screen-detected cancer (X2= 11.481, p=0.003) and more likely to have a high-grade cancer (X2=14.383, p=0.006). There was no difference in mastectomy rate (X2=1.698, p=0.428).Conclusion: Iranian-born women treated for breast cancer in Australia were younger, had higher-grade tumours and were less likely to have a screen-detected cancer than Australian-born women or women born in other countries. Strategies to encourage screening participation in Iranian-born women are required. Support for these women is required as they are more likely to receive toxic treatments (chemotherapy and extended adjuvant endocrine therapy) due to younger age and higher grade tumours.