Targeted axillary dissection: worldwide variations in clinical practice.

PURPOSE: Targeted axillary dissection (TAD) for the axillary staging of clinically node-positive (cN +) breast cancer patients converting to clinically node negative post neoadjuvant chemotherapy (NAC), has gained popularity due to its minimal false negative rate and low arm morbidity. The aim of this study is to shed more light on the variation in the clinical practice globally in terms of indications and perceived limitations of TAD. METHODS: A panel of expert breast surgeons constructed a structured questionnaire comprising of 18 questions and asked surgeons worldwide for their opinions and routine practice on TAD. The questionnaire was electronically distributed and answers were collected between May 1st and August 1st 2022. RESULTS: Responses included 137 entries from 36 countries. Of them, 73.7% consider TAD for cN + patients planned to receive NAC. Among them, the greatest number of respondents (45%) perform the procedure for tumours up to T3, whereas 27% regardless of T-stage. The majority (42%) perform TAD on patients with 1-3 positive nodes and only 30% consider TAD when matted nodes are present. HER2 positive and Triple Negative subtypes are more likely to undergo TAD than Luminal A and B (86%, 79.1%, 39.5%, and 62.8%, respectively). Maximum acceptable lymph node burden is median 3 nodes for any subtype with a tendency to accept more positive nodes for Triple Negative. CONCLUSION: This study demonstrates the differences in current practice regarding TAD as well as the fact that the biology of the tumour heavily affects the method of axillary staging.

Postoperative complications and surgical outcomes of robotic versus conventional nipple-sparing mastectomy in breast cancer: meta-analysis.

BACKGROUND: Breast cancer is the most common cancer worldwide, with remarkable advances in early diagnosis, systemic treatments, and surgical techniques. Robotic nipple-sparing mastectomy has been trialled; however, the complication rates, surgical outcomes, and oncological safety of this approach remain obscure. METHODS: A systematic search of the literature was conducted from conception until September 2022. Studies examining complications and operative variables where robotic nipple-sparing mastectomy was compared with conventional nipple-sparing mastectomy were included. Primary study outcomes were complications (Clavien-Dindo grade III complications, skin or nipple necrosis, seroma, haematoma, infection, implant loss, and wound dehiscence) and oncological safety (recurrence and positive margins). The secondary outcomes included operative variables, length of stay, cost-effectiveness, learning curve, and aesthetic outcome. RESULTS: A total of seven studies of overall fair quality, involving 1674 patients, were included in the systematic review and meta-analysis. Grade 3 complications were reduced in robotic nipple-sparing mastectomy without statistical significance (OR 0.60 (95 per cent c.i. 0.35 to 1.05)). Nipple necrosis was significantly reduced in robotic nipple-sparing mastectomy (OR 0.54 (95 per cent c.i. 0.30 to 0.96); P = 0.03; I2 = 15 per cent). Operating time (mean difference +58.81 min (95 per cent c.i. +28.19 to +89.44 min); P = 0.0002) and length of stay (mean difference +1.23 days (95 per cent c.i. +0.64 to +1.81 days); P < 0.0001) were significantly increased in robotic nipple-sparing mastectomy, whereas the opposite was true for blood loss (mean difference -53.18 ml (95 per cent c.i. -71.78 to -34.58 ml); P < 0.0001). CONCLUSION: Whilst still in its infancy, robotic breast surgery may become a viable option in breast surgery. Nonetheless, the oncological safety of this approach requires robust assessment.

Robotic nipple-sparing mastectomy has been tried, but it is still not clear how often complications happen or how much better it is for cancer patients than conventional nipple-sparing mastectomy. The aim of this study was to compare robotic nipple-sparing mastectomy with conventional nipple-sparing mastectomy. A thorough search of all articles was performed from the start to September 2022. The studies that compared robotic nipple-sparing mastectomy with conventional nipple-sparing mastectomy in terms of problems and surgical factors were included. Complications and cancer outcomes (recurrence and positive margins) were the most important things that the study looked at. Surgical time, blood loss, length of hospital stay, cost-effectiveness, learning curve, and patient-reported outcome measures were some of the other things that were studied. This systematic review and meta-analysis looked at seven studies with fair quality and included 1674 patients. Even though there were fewer major problems with robotic nipple-sparing mastectomy, the difference was not significant. In robotic nipple-sparing mastectomy, there was less nipple necrosis, but the overall time it took to operate was much longer and the cost was higher. The average amount of bleeding was less in robotic nipple-sparing mastectomy. The robotic nipple-sparing mastectomy method had a better patient-reported outcome and a steep learning curve. Robotic nipple-sparing mastectomy is a safe method, with fewer problems than other methods. Future studies should look into if it is safe for cancer patients in the long run.

Chest wall perforator flaps for breast reconstruction: international survey on attitudes and training needs.

BACKGROUND: Volume replacement using chest wall perforator flaps (CWPFs) is a promising technique to reduce mastectomy rates without sacrificing function or aesthetics. Owing to limited availability of the technique, only a minority of patients currently have access to CWPF procedures. METHODS: An international web-based survey was disseminated through social media, dedicated webpages, and national and international societies for breast surgery. The survey explored surgeons' attitudes towards CWPFs and their perceived training needs. RESULTS: Of 619 respondents, 88.4 per cent agreed that CWPF surgery was desirable, with one-third offering it and performing a median of 10 (i.q.r. 5-15) procedures annually. They were more likely to be senior (OR 1.35, 95 per cent c.i. 1.18 to 1.55; P < 0.001), with formal oncoplastic training (OR 4.80, 3.09 to 7.48; P < 0.001), and working in larger units (OR 1.18, 1.03 to 1.35; P = 0.018) with a free-flap (OR 1.62, 1.06 to 2.48; P = 0.025) or CWPF (OR 3.02, 1.87 to 4.89; P < 0.001) service available. In cluster and latent class analysis, none showed high cohesion with performance of CWPF surgery. CONCLUSION: There is a discrepancy between perceived importance and availability of CWPF surgery, indicating that optimal training is needed.

Peri-tumoural spatial distribution of lipid composition and tubule formation in breast cancer.

BACKGROUND: Response guided treatment in breast cancer is highly desirable, but the effectiveness is only established based on residual cellularity from histopathological analysis after surgery. Tubule formation, a key component of grading score, is directly associated with cellularity, with significant implications on prognosis. Peri-tumoural lipid composition, a potential marker, can be rapidly mapped across the entire breast using novel method of chemical shift-encoded imaging, enabling the quantification of spatial distribution. We hypothesise that peri-tumoural spatial distribution of lipid composition is sensitive to tumour cellular differentiation and proliferative activity. METHODS: Twenty whole tumour specimens freshly excised from patients with invasive ductal carcinoma (9 Score 2 and 11 Score 3 in tubule formation) were scanned on a 3 T clinical scanner (Achieva TX, Philips Healthcare). Quantitative lipid composition maps were acquired for polyunsaturated, monounsaturated, and saturated fatty acids (PUFA, MUFA, SFA). The peri-tumoural spatial distribution (mean, skewness, entropy and kurtosis) of each lipid constituent were then computed. The proliferative activity marker Ki-67 and tumour-infiltrating lymphocytes (TILs) were assessed histologically. RESULTS: For MUFA, there were significant differences between groups in mean (p = 0.0119), skewness (p = 0.0116), entropy (p = 0.0223), kurtosis (p = 0.0381), and correlations against Ki-67 in mean (ρ = -0.5414), skewness (ρ = 0.6045) and entropy (ρ = 0.6677), and TILs in mean (ρ = -0.4621). For SFA, there were significant differences between groups in mean (p = 0.0329) and skewness (p = 0.0111), and correlation against Ki-67 in mean (ρ = 0.5910). For PUFA, there was no significant difference in mean, skewness, entropy or kurtosis between the groups. CONCLUSIONS: There was an association between peri-tumoural spatial distribution of lipid composition with tumour cellular differentiation and proliferation. Peri-tumoural lipid composition imaging might have potential in non-invasive quantitative assessment of patients with breast cancer for treatment planning and monitoring.

Intra-tumoural lipid composition and lymphovascular invasion in breast cancer via non-invasive magnetic resonance spectroscopy.

OBJECTIVES: Despite improved survival due to new treatments, the 10-year survival rate in patients with breast cancer is approximately 75%. Lymphovascular invasion (LVI), a prognostic marker independent from histological grade and stage, can only be fully determined at final histological examination. Lipid composition is deregulated in tumour via de novo lipogenesis, with alteration in lipogenic genes in LVI. We hypothesise alteration in lipid composition derived from novel non-invasive spectroscopy method is associated with LVI positivity. METHODS: Thirty female patients (age 39-78) with invasive ductal carcinoma were enrolled, with 13 LVI negative and 17 LVI positive. Saturated, monounsaturated, polyunsaturated fatty acids and triglycerides (SFA, MUFA, PUFA and TRG) were quantified from ex vivo breast tumours freshly excised from patients on a 3 T clinical MRI scanner, and proliferative activity marker Ki-67 and serotonin derived histologically. RESULTS: There were significantly lower MUFA (p = 0.0189) in LVI positive (median: 0.37, interquartile range (IQR): 0.25-0.64) than negative (0.63, 0.49-0.96). There were significantly lower TRG (p = 0.0226) in LVI positive (1.32, 0.95-2.43) than negative (2.5, 1.92-4.15). There was no significant difference in SFA (p = 0.6009) or PUFA (p = 0.1641). There was no significant correlation between lipid composition against Ki-67 or serotonin, apart from a borderline negative correlation between PUFA and serotonin (r = - 0.3616, p = 0.0496). CONCLUSION: Lipid composition might provide a biomarker to study lymphovascular invasion in breast cancer. KEY POINTS: • Monounsaturated fatty acids in lymphovascular invasion (LVI) positive invasive breast carcinoma were significantly lower than that in LVI negative. • Triglycerides in LVI positive invasive breast carcinoma were significantly lower than that in LVI negative. • Lipid composition from MR spectroscopy reflects the rate of de novo lipogenesis and provides a potential biomarker independent from histological grade and stage.

Lactate concentration in breast cancer using advanced magnetic resonance spectroscopy.

BACKGROUND: Precision medicine in breast cancer demands markers sensitive to early treatment response. Aerobic glycolysis (AG) upregulates lactate dehydrogenase A (LDH-A) with elevated lactate production; however, existing approaches for lactate quantification are either invasive or impractical clinically. METHODS: Thirty female patients (age 39-78 years, 15 grade II and 15 grade III) with invasive ductal carcinoma were enrolled. Lactate concentration was quantified from freshly excised whole tumours with double quantum filtered (DQF) magnetic resonance spectroscopy (MRS), and Nottingham Prognostic Index (NPI), LDH-A and proliferative marker Ki-67 were assessed histologically. RESULTS: There was a significantly higher lactate concentration (t = 2.2224, p = 0.0349) in grade III (7.7 ± 2.9 mM) than in grade II (5.5 ± 2.4 mM). Lactate concentration was correlated with NPI (ρ = 0.3618, p = 0.0495), but not with Ki-67 (ρ = 0.3041, p = 0.1023) or tumour size (r = 0.1716, p = 0.3645). Lactate concentration was negatively correlated with LDH-A (ρ = -0.3734, p = 0.0421). CONCLUSION: Our results showed that lactate concentration in whole breast tumour from DQF MRS is sensitive to tumour grades and patient prognosis.

Diagnosis and management of chyle leak following axillary dissection.

Chyle leak following oncological breast and axillary surgery is a rare complication with small number of reported cases in the literature and little formal guidance regarding management. We present a review of the current literature and further related guidance from other specialties, along with suggested strategies for identification, diagnosis and management of this uncommon but potentially significant complication.

Oncoplastic breast surgery in Europe.

Oncoplastic breast surgery (OPS) has become an integral part of breast cancer surgery for both breast conservation and mastectomies. In recent years, the emphasis on early detection and the advances in systemic and locoregional therapy has improved prognosis leading to an increased focus on survivorship and quality of life issues including patients' short and long-term aesthetic appearance as a key part of the surgical management. There is a significant variation across Europe in the type of specialist performing breast cancer surgery and the provision of OPS as such. In the traditional model, breast cancer care was provided by gynecologists in some countries, general surgeons, surgical oncologists, and breast surgeons in others. However recently, surgeons throughout Europe have extended their skill-base to include level 1 and 2 OPS and implant- and pedicle-flap based breast reconstruction. For breast surgeons to become proficient in these techniques, a standardized level of training and expertise is needed. The European Society of Mastology (EUSOMA) set standards for a specialist health professional in the field of breast cancer, the European Union of Medical Specialists (UEMS) examinations and the global curriculum that was developed by the American Society of Surgical Oncology (SSO) and the European Society of Surgical Oncology (ESSO) aims to improve standards of OPS practice across Europe. The new generation of breast surgeons, therefore, should be equipped with the necessary skill set to provide high quality OPS while keeping abreast of novel technologies and techniques aiming to provide patients with excellent long-term quality of life.

Spatial heterogeneity of peri-tumoural lipid composition in postmenopausal patients with oestrogen receptor positive breast cancer.

Deregulation of lipid composition in adipose tissue adjacent to breast tumour is observed in ex vivo and animal models. Novel non-invasive magnetic resonance imaging (MRI) allows rapid lipid mapping of the human whole breast. We set out to elucidate the spatial heterogeneity of peri-tumoural lipid composition in postmenopausal patients with oestrogen receptor positive (ER +) breast cancer. Thirteen participants (mean age, 62 ± [SD] 6 years) with ER + breast cancer and 13 age-matched postmenopausal healthy controls were scanned on MRI. The number of double bonds in triglycerides was computed from MRI images to derive lipid composition maps of monounsaturated, polyunsaturated, and saturated fatty acids (MUFA, PUFA, SFA). The spatial heterogeneity measures (mean, median, skewness, entropy and kurtosis) of lipid composition in the peri-tumoural region and the whole breast of participants and in the whole breast of controls were computed. The Ki-67 proliferative activity marker and CD163 antibody on tumour-associated macrophages were assessed histologically. Mann Whitney U or Wilcoxon tests and Spearman's coefficients were used to assess group differences and correlations, respectively. For comparison against the whole breast in participants, peri-tumoural MUFA had a lower mean (median (IQR), 0.40 (0.02), p < .001), lower median (0.42 (0.02), p < .001), a negative skewness with lower magnitude (- 1.65 (0.77), p = .001), higher entropy (4.35 (0.64), p = .007) and lower kurtosis (5.13 (3.99), p = .001). Peri-tumoural PUFA had a lower mean (p < .001), lower median (p < .001), a positive skewness with higher magnitude (p = .005) and lower entropy (p = .002). Peri-tumoural SFA had a higher mean (p < .001), higher median (p < .001), a positive skewness with lower magnitude (p < .001) and lower entropy (p = .012). For comparison against the whole breast in controls, peri-tumoural MUFA had a negative skewness with lower magnitude (p = .01) and lower kurtosis (p = .009), however there was no difference in PUFA or SFA. CD163 moderately correlated with peri-tumoural MUFA skewness (rs = - .64), PUFA entropy (rs = .63) and SFA skewness (rs = .59). There was a lower MUFA and PUFA while a higher SFA, and a higher heterogeneity of MUFA while a lower heterogeneity of PUFA and SFA, in the peri-tumoural region in comparison with the whole breast tissue. The degree of lipid deregulation was associated with inflammation as indicated by CD163 antibody on macrophages, serving as potential marker for early diagnosis and response to therapy.

Post-mastectomy radiation therapy after breast reconstruction: from historic dogmas to practical expert agreements based on a large literature review of surgical and radiation therapy considerations.

Breast reconstruction (BR) after mastectomy is important to consider for a woman's body image enhancement and psychological well-being. Although post-mastectomy radiation (PMRT) significantly improves the outcome of patients with high-risk breast cancer (BC), PMRT after BR may affect cosmetic outcomes and may compromise the original goal of improving quality of life (QoL). With the lack of practical guidelines, it seems essential to work on a consensus and provide some "expert agreements" to offer patients the best option for PMRT after BR. We report a global "expert agreement" that results from a critical review of the literature on BR and PMRT during the 6th international multidisciplinary breast conference in March 2023.

Comprehending the impact of #Breastcancer, #Breastsurgery and related hashtags on Twitter: A content and social network cross-sectional analysis #Breastcancer#Breastsurgery.

BACKGROUND: Early detection along with improved locoregional and systemic therapies have decreased breast cancer mortality and allowed for the clinical implementation of breast conserving surgical options, in turn reducing the clinical and psychosocial impact of mastectomy. To what extend this has been successfully conveyed through social media for breast cancer awareness, has not been previously investigated. METHODS: This study presents a content and social network cross-sectional descriptive study of Twitter and Google trends data worldwide from platform launch (2006 and 2004 respectively) until May 15th, 2022, in agreement with the STROBE guidelines. Tweets associated with the hashtags #Breastcancer, #Breastsurgery, #Oncoplasticsurgery, #Mastectomy, #Breastreconstruction, #Breastconservingsurgery were licensed and downloaded through the Vincitas and Tweetbinder online platforms. Associated available demographics, namely username, biography, location, date and language of post, were extracted from the Twitter dataset while interest percentage, location and language of search were extracted from the Google trends dataset. RESULTS: A total of 390111 unique tweets were generated by 127284 unique users, with 2 users engaging with all six hashtags. Original tweets constituted on average 39.1% [Min 30.7% to max 47.2%] of the total. Hashtag frequency increased on Twitter for all six searches during October, the breast-cancer awareness month, but not on Google trends. Cancer survivors engaged much more often with the hashtag #Breastcancer and #Mastectomy, whereas #Breastsurgery, #Oncoplasticsurgery, #Breastconservingsurgery, #Breastreconstruction were mostly used by health professionals. CONCLUSION: In this large qualitative and quantitative dataset, geo-temporal oscillations on Twitter and Google trends for hashtags relevant with breast cancer provide preliminary insights on information flow and user engagement. Understanding the effective use of social media platforms may provide the niche for disseminating evidence and promoting education on the surgical options of patients with breast cancer.

The Evolution of Educational Events during the COVID-19 Pandemic: The Experience of G.Re.T.A. Foundation.

Introduction: The educational and professional lives of everyone have significantly been affected by the COVID-19 pandemic. Many courses and meetings traditionally structured and organized as face-to-face events have been transformed into virtual events. Methods: We report on the experience of G.Re.T.A. Fondazione in organizing international conferences, webinars, and masterclasses on oncoplastic and aesthetic breast surgery before, during, and after the pandemic. Results: The organization of the meetings as online or hybrid events allowed to maintain a high number of participants with numbers being in line with those achieved in the traditional face-to-face events or even showing an increased number of participants, in particular from countries not traditionally involved such as Saudi Arabia, the United Arab Emirates, India, and Russian Federation. Discussion: We think that the hybrid modality is likely to become a gold standard, even though purely online meetings will still survive in the post-pandemic era. Webinars are frugal and highly efficient events that can easily reach a worldwide audience with acceptable interaction.

Non-Surgical Site Pain in Women following Breast Cancer Surgery: A Systematic Review and Meta-Analysis.

Background: Chronic pain after breast cancer surgery affects up to 60% of patients. Evidence supports the fact that pain outwith the surgical site is a significant issue. This systematic review and meta-analysis sought to evaluate the prevalence of non-surgical site pain (NSSP) in women after breast cancer surgery at 6 months post-operatively. Methods: Adult women with a confirmed breast cancer diagnosis who had undergone breast cancer surgery were identified. The outcome pursued was pain outwith the surgical site measured on either NRS/VRS or VAS rating scale. CENTRAL, Embase, PubMed, MEDLINE, CINAHL, PsycInfo, Web of Science, and Scopus were searched to identify studies that examined NSSP after breast cancer surgery at 6 months. Data were gathered via pre-piloted Excel forms and analysed both quantitively and qualitatively. Meta-analysis was carried out using a random-effects model to assess risk difference with 95% confidence interval (CI). Results: A total of sixteen studies were identified for inclusion. Eleven studies failed to provide sufficient data and consequently were analysed qualitatively. Five studies were adequate for quantitative analysis, including a total of 995 patients. Meta-analysis identified a risk difference of 18% (95% CI: 5-31%) between patients who had breast cancer surgery and a reference, however, this is low-quality evidence. Conclusion: This review has highlighted that breast cancer surgery increases the risk of pain outwith the surgical site postoperatively. It was additionally identified that NSSP data are often gathered in research yet rarely presented in results or highlighted as a primary outcome. As the quality of evidence was low, research specifying NSSP as a primary outcome is required to provide more certainty.

The Role of Social Media in Breast Cancer Care and Survivorship: A Narrative Review.

Background: Female breast cancer (BC) is the most diagnosed cancer and the leading cause of malignancy-related death worldwide. With the widespread utilisation of the Internet, social media has presented an invaluable yet underemployed tool in the context of BC medical information dissemination, support hub formation, and patient empowerment. Summary: In this narrative review, we explore the untapped potential of social media in this context, caveats, and future directions that may aid in formulating a new era of patient led, in addition to patient-centred care. Key Messages: Social media represents a powerful tool with significant potential to enable the seeking and sharing of BC-related information, and enhance patient education, communication, engagement, and empowerment. However, its use is associated with a number of limitations, including confidentiality and addiction issues, excessive and inaccurate information, and a possibility of jeopardising the patient-doctor relationship. Further research is needed to shed more light on this topic.

The Role of Social Media and Breast Cancer: How Does It Impact Patients?

Introduction: Patients are increasingly turning to other sources for their health information. Social media has become mainstream, and the easy access to online communities, health professionals, and shared experiences of other patients has made social media a place where many patients turn to. Methods: In this qualitative report, 2 patients who have had breast cancer describe the reasons why they use social media, what they perceive the advantages and disadvantages are, and what the impact of social media has been through their cancer treatment and beyond. Results: The reasons why patients turn to social media are varied. These can include information gathering, peer support, shared experiences, and advocacy. There appear to be advantages and disadvantages; however, overall, the impact seems to be a positive one when used judiciously. Discussion: It is clear that social media has a role to play in healthcare, whether by providing meaningful social connections, delivery of information, or psychological support. Healthcare professionals perhaps should consider the importance of social media in their practice.

Germline Testing Around the Globe: Challenges in Different Practice Settings.

Cancer is an increasing global public health burden. Lately, more emphasis has emerged on the importance of heredity in cancer, mostly driven by the introduction of germline genetic variants-directed therapeutics. It is true that 40% of cancer risk is attributed to modifiable environmental and lifestyle factors; still, 16% of cancers could be heritable, accounting for 2.9 of the 18.1 million cases diagnosed worldwide. At least two third of those will be diagnosed in countries with limited resources-low- and middle-income countries, especially where high rates of consanguine marriage and early age at diagnosis are already prevalent. Both are hallmarks of hereditary cancer. This creates a new opportunity for prevention, early detection, and recently therapeutic intervention. However, this opportunity is challenged by many obstacles along the path to addressing germline testing in patients with cancer in the clinic worldwide. Global collaboration and expertise exchange are important to bridge the knowledge gap and facilitate practical implementation. Adapting existing guidelines and prioritization according to local resources are essential to address the unique needs and overcome the unique barriers of each society.

Natural Language Processing to Extract Meaningful Information from a Corpus of Written Knowledge in Breast Cancer: Transforming Books into Data.

Introduction: Books and papers are the most relevant source of theoretical knowledge for medical education. New technologies of artificial intelligence can be designed to assist in selected educational tasks, such as reading a corpus made up of multiple documents and extracting relevant information in a quantitative way. Methods: Thirty experts were selected transparently using an online public call on the website of the sponsor organization and on its social media. Six books edited or co-edited by members of this panel containing a general knowledge of breast cancer or specific surgical knowledge have been acquired. This collection was used by a team of computer scientists to train an artificial neural network based on a technique called Word2Vec. Results: The corpus of six books contained about 2.2 billion words for 300d vectors. A few tests were performed. We evaluated cosine similarity between different words. Discussion: This work represents an initial attempt to derive formal information from textual corpus. It can be used to perform an augmented reading of the corpus of knowledge available in books and papers as part of a discipline. This can generate new hypothesis and provide an actual estimate of their association within the expert opinions. Word embedding can also be a good tool when used in accruing narrative information from clinical notes, reports, etc., and produce prediction about outcomes. More work is expected in this promising field to generate "real-world evidence."

Towards detection of early response in neoadjuvant chemotherapy of breast cancer using Bayesian intravoxel incoherent motion.

Introduction: The early identification of good responders to neoadjuvant chemotherapy (NACT) holds a significant potential in the optimal treatment of breast cancer. A recent Bayesian approach has been postulated to improve the accuracy of the intravoxel incoherent motion (IVIM) model for clinical translation. This study examined the prediction and early sensitivity of Bayesian IVIM to NACT response. Materials and methods: Seventeen female patients with breast cancer were scanned at baseline and 16 patients were scanned after Cycle 1. Tissue diffusion and perfusion from Bayesian IVIM were calculated at baseline with percentage change at Cycle 1 computed with reference to baseline. Cellular proliferative activity marker Ki-67 was obtained semi-quantitatively with percentage change at excision computed with reference to core biopsy. Results: The perfusion fraction showed a significant difference (p = 0.042) in percentage change between responder groups at Cycle 1, with a decrease in good responders [-7.98% (-19.47-1.73), n = 7] and an increase in poor responders [10.04% (5.09-28.93), n = 9]. There was a significant correlation between percentage change in perfusion fraction and percentage change in Ki-67 (p = 0.042). Tissue diffusion and pseudodiffusion showed no significant difference in percentage change between groups at Cycle 1, nor was there a significant correlation against percentage change in Ki-67. Perfusion fraction, tissue diffusion, and pseudodiffusion showed no significant difference between groups at baseline, nor was there a significant correlation against Ki-67 from core biopsy. Conclusion: The alteration in tumour perfusion fraction from the Bayesian IVIM model, in association with cellular proliferation, showed early sensitivity to good responders in NACT. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT03501394, identifier NCT03501394.