The Impact of Bariatric Surgery on Breast Cancer Recurrence: Case Series and Review of Literature

Clinical Guidance for Dosing and Monitoring Oral Antihormonal Drugs in Patients with Breast Cancer After Roux-en-Y Gastric Bypass

ABSTRACT

Obesity is associated with an increased risk of cancers, such as breast cancer. Roux-en-Y gastric bypass (RYGB) is a common surgical intervention used to induce weight loss, reduce comorbidities, and improve overall survival. Due to alterations in the gastrointestinal tract, RYGB is associated with changes in oral drug disposition, which can affect treatment outcomes. Oral antihormonal agents were monitored in 9 patients who previously underwent RYGB. The results of therapeutic drug monitoring and estradiol concentrations were analyzed, and a review of the relevant literature was performed. As only 1 of the 6 patients prescribed tamoxifen achieved a therapeutic endoxifen concentration with the standard dose of 20 mg/d, a higher starting dose of 40 mg/d was recommended to increase the probability of attaining a therapeutic plasma concentration. All patients with decreased CYP2D6 metabolic activity could not achieve therapeutic plasma concentrations; therefore, CYP2D6 genotyping was recommended before the initiation of tamoxifen therapy to identify patients who should be switched to aromatase inhibitors. Anastrozole and letrozole exposure in patients who underwent RYGB patients appeared sufficient, with no dose adjustment required. However, until more data become available, monitoring aromatase inhibitor efficacy is recommended. Monitoring the drug concentrations is a viable option; however, only indicative data on therapeutic drug monitoring are available. Therefore, estradiol concentrations should be measured.

The relation between excess adiposity and breast cancer in women: Clinical implications and management

BACKGROUND

Breast cancer (BC) is the most common cancer in women. While the combination of improved screening, earlier detection, and advances in therapeutics has resulted in lower BC mortality, BC survivors are now increasingly dying of cardiovascular disease. Cardiovascular disease in the leading cause of non-cancer related mortality among BC survivors. This situation underscores the critical need to research the role of modifiable cardiometabolic risk factors, such as excess adiposity, that will affect BC remission, long-term survivorship, and overall health and quality of life.

PURPOSE

First, this review summarizes the evidence on the connection between adipose tissue and BC. Then we review the data on weight trends after BC diagnosis with a focus on the effect of weight gain on BC recurrence and BC- and non-BC-related death. Finally, we provide a guide for weight management in BC survivors, considering the available data on the effect of weight loss interventions on BC.

The Effectiveness of Metabolic Bariatric Surgery in Preventing Gynecologic Cancer - from Pathophysiology to Clinical Outcomes

Obesity and cancer represent two pandemics of current civilization, the progression of which has followed parallel trajectories. To time, thirteen types of malignancies have been recognized as obesity-related cancers, including breast (in postmenopausal women), endometrial, and ovarian cancer. Pathophysiologic mechanisms that connect the two entities include insulin resistance, adipokine imbalance, increased peripheral aromatization and estrogen levels, tissue hypoxia, and disrupted immunity in the cellular milieu. Beyond the connection of obesity to carcinogenesis at a molecular and cellular level, clinicians should always be cognizant of the fact that obesity might have secondary impacts on the diagnosis and treatment of gynecologic cancer, including limited access to effective screening programs, resistance to chemotherapy and targeted therapies, persisting lymphedema, etc. Metabolic bariatric surgery represents an attractive intervention not only for decreasing the risk of carcinogenesis in high-risk women living with obesity but most importantly as a measure to improve disease-specific and overall survival in patients with diagnosed obesity-related gynecologic malignancies. The present narrative review summarizes current evidence on the underlying pathophysiologic mechanisms, the clinical data, and the potential applications of metabolic bariatric surgery in all types of gynecologic cancer, including breast, endometrial, ovarian, cervical, vulvar, and vaginal.

Gastric cancer after Bariatric Bypass Surgery. Do they relate? (A Systematic Review)

Bariatric bypass surgery has been an effective treatment for morbid obesity. However, there is an increasing number of reported cases of gastric cancer after bypass surgery. Our systematic review showed an increasing trend of gastric cancer cases after bariatric bypass surgery in the last decade, mostly located in the excluded stomach (77%) and diagnosed in an advanced stage. In addition to known risk factors such as tobacco smoking (17%), H. pylori infection (6%), and family history of gastric cancer (3%), bile reflux, a recently proposed cancer-promoting factor, was also estimated in 18% of the cases. Our data suggest that gastric cancer risk assessment should be considered before gastric bypass surgery, and further investigations are needed to determine the value of post-operative gastric cancer surveillance.

Effects of different weight loss programmes on oncological outcomes following curative resection of digestive tract cancers

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the effect of different weight loss programmes on oncological outcomes following curative resection of GI tract cancers. 

The role of obesity and bariatric surgery-induced weight loss in breast cancer

Obesity is a complex metabolic condition considered a worldwide public health crisis, and a deeper mechanistic understanding of obesity-associated diseases is urgently needed. Obesity comorbidities include many associated cancers and are estimated to account for 20% of female cancer deaths in the USA. Breast cancer, in particular, is associated with obesity and is the focus of this review. The exact causal links between obesity and breast cancer remain unclear. Still, interactions have emerged between body mass index, tumor molecular subtype, genetic background, and environmental factors that strongly suggest obesity influences the risk and progression of certain breast cancers. Supportive preclinical research uses various diet-induced obesity models to demonstrate that weight loss, via dietary interventions or changes in energy expenditure, reduces the onset or progression of breast cancers. Ongoing and future studies are now aimed at elucidating the underpinning mechanisms behind weight-loss-driven observations to improve therapy and outcomes in patients with breast cancer and reduce risk. This review aims to summarize the rapidly emerging literature on obesity and weight loss strategies with a focused discussion of bariatric surgery in both clinical and preclinical studies detailing the complex interactions between metabolism, immune response, and immunotherapy in the setting of obesity and breast cancer.

Clinical interventions to break the obesity and cancer link: a narrative review

Excess body weight is a significant risk factor for the development and recurrence of many types of cancer. Patients with a history or current diagnosis of cancer who are overweight or have obesity have an increased risk of cancer treatment-related morbidity, recurrence, and decreased quality of life. Weight loss and maintenance of a healthy body weight may reduce cancer morbidity and recurrence in cancer survivors. While guidelines for cancer survivorship elaborate sufficiently on lifestyle interventions, little guidance is provided when considering additional therapies like anti-obesity pharmacotherapy or bariatric surgery for weight loss. This review will highlight and address current recommendations and feasible interventions that clinicians may consider to further reduce the incidence and recurrence of cancer in patients with obesity.

Chimeric Antigen Receptor (CAR)-T Cell Immunotherapy Against Thoracic Malignancies: Challenges and Opportunities

Different from surgery, chemical therapy, radio-therapy and target therapy, Chimeric antigen receptor-modified T (CAR-T) cells, a novel adoptive immunotherapy strategy, have been used successfully against both hematological tumors and solid tumors. Although several problems have reduced engineered CAR-T cell therapeutic outcomes in clinical trials for the treatment of thoracic malignancies, including the lack of specific antigens, an immunosuppressive tumor microenvironment, a low level of CAR-T cell infiltration into tumor tissues, off-target toxicity, and other safety issues, CAR-T cell treatment is still full of bright future. In this review, we outline the basic structure and characteristics of CAR-T cells among different period, summarize the common tumor-associated antigens in clinical trials of CAR-T cell therapy for thoracic malignancies, and point out the current challenges and new strategies, aiming to provide new ideas and approaches for preclinical experiments and clinical trials of CAR-T cell therapy for thoracic malignancies.

Response to immune checkpoint blockade improved in pre-clinical model of breast cancer after bariatric surgery

Bariatric surgery is a sustainable weight loss approach, including vertical sleeve gastrectomy (VSG). Obesity exacerbates tumor growth, while diet-induced weight loss impairs progression. It remains unknown how bariatric surgery-induced weight loss impacts cancer progression or alters response to therapy. Using a pre-clinical model of obesity followed by VSG or diet-induced weight loss, breast cancer progression and immune checkpoint blockade therapy were investigated. Weight loss by VSG or weight-matched dietary intervention before tumor engraftment protected against obesity-exacerbated tumor progression. However, VSG was not as effective as diet in reducing tumor burden despite achieving similar weight and adiposity loss. Leptin did not associate with changes in tumor burden; however, circulating IL-6 was elevated in VSG mice. Uniquely, VSG tumors displayed elevated inflammation and immune checkpoint ligand PD-L1+ myeloid and non-immune cells. VSG tumors also had reduced T lymphocytes and markers of cytolysis, suggesting an ineffective anti-tumor microenvironment which prompted investigation of immune checkpoint blockade. While obese mice were resistant to immune checkpoint blockade, anti-PD-L1 potently impaired tumor progression after VSG through improved anti-tumor immunity. Thus, in formerly obese mice, surgical weight loss followed by immunotherapy reduced breast cancer burden. Finally, we compared transcriptomic changes in adipose tissue after bariatric surgery from patients and mouse models. A conserved bariatric surgery-associated weight loss signature (BSAS) was identified which significantly associated with decreased tumor volume. Findings demonstrate conserved impacts of obesity and bariatric surgery-induced weight loss pathways associated with breast cancer progression.

As the number of people classified as obese rises globally, so do obesity-related health risks. Studies show that people diagnosed with obesity have inflammation that contributes to tumor growth and their immune system is worse at detecting cancer cells. But weight loss is not currently used as a strategy for preventing or treating cancer.

Surgical procedures for weight loss, also known as ‘bariatric surgeries’, are becoming increasingly popular. Recent studies have shown that individuals who lose weight after these treatments have a reduced risk of developing tumors. But how bariatric surgery directly impacts cancer progression has not been well studied: does it slow tumor growth or boost the anti-tumor immune response?

To answer these questions, Sipe et al. compared breast tumor growth in groups of laboratory mice that were obese due to being fed a high fat diet. The first group of mice lost weight after undergoing a bariatric surgery in which part of their stomach was removed. The second lost the same amount of weight but after receiving a restricted diet, and the third underwent a fake surgery and did not lose any weight. The experiments found that surgical weight loss cuts breast cancer tumor growth in half compared with obese mice. But mice who lost the same amount of weight through dietary restrictions had even less tumor growth than surgically treated mice.

The surgically treated mice who lost weight had more inflammation than mice in the two other groups, and had increased amounts of proteins and cells that block the immune response to tumors. Giving the surgically treated mice a drug that enhances the immune system’s ability to detect and destroy cancer cells reduced inflammation and helped shrink the mice’s tumors. Finally, Sipe et al. identified 54 genes which were turned on or off after bariatric surgery in both mice and humans, 11 of which were linked with tumor size.

These findings provide crucial new information about how bariatric surgery can impact cancer progression. Future studies could potentially use the conserved genes identified by Sipe et al. to develop new ways to stimulate the anti-cancer benefits of weight loss without surgery.

Obesity and breast cancer: Preventive and therapeutic possibilities for bariatric surgery

Breast cancer is the most common and second deadliest malignancy in women. With rising obesity rates and building evidence for a strong association with obesity, the incidence of breast cancer can be expected to increase. Weight loss reduces breast cancer risk, the mechanisms of which are still poorly understood. As an effective therapy for obesity, bariatric surgery may be a powerful tool in breast cancer prevention and treatment. This review details the potential physiologic mechanisms that may underlie this association, as well as recently published studies that reinforce the link between bariatric surgery and a reduction in incident breast cancer. The use of bariatric surgery as an adjunct therapy in endometrial cancer also raises the potential for similar use in select breast cancer patients. Despite the expanding potential applications of bariatric surgery in this field, publications to date have been strictly observational, highlighting a need for future clinical trials.

Breast Cancer Diet "BCD": A Review of Healthy Dietary Patterns to Prevent Breast Cancer Recurrence and Reduce Mortality

Breast cancer (BC) represents the most common cancer in women, while overweight and obesity are the second preventable cause of cancer. Weight gain and fat accumulation are common after BC diagnosis; moreover, weight gain during the treatment decreases the survival rate and increases the risk of recurrence in breast cancer survivors (BCS). To reduce the risk of second primary cancer or BC recurrence, and all-cause mortality in BCS, multiple interventions have been investigated to obtain reduction in weight, BMI and/or waist circumference. The aim of this narrative review is to analyze evidence on BCS for their risk of recurrence or mortality related to increased weight or fat deposition, and the effects of interventions with healthy dietary patterns to achieve a proper weight and to reduce fat-related risk. The primary focus was on dietary patterns instead of single nutrients and supplements, as the purpose was to investigate on secondary prevention in women free from disease at the end of their cancer treatment. In addition, BC relation with insulin resistance, dietary carbohydrate, and glycemic index/glycemic load is discussed. In conclusion, obesity and overweight, low rates of physical activity, and hormone receptor-status are associated with poorer BC-treatment outcomes. To date, there is a lack of evidence to suggest which dietary pattern is the best approach for weight management in BCS. In the future, multimodal lifestyle interventions with dietary, physical activity and psychological support after BC diagnosis should be studied with the aim of reducing the risk of BC recurrence or mortality.

Targeting obesity-related dysfunction in hormonally driven cancers

Obesity is a risk factor for at least 13 different types of cancer, many of which are hormonally driven, and is associated with increased cancer incidence and morbidity. Adult obesity rates are steadily increasing and a subsequent increase in cancer burden is anticipated. Obesity-related dysfunction can contribute to cancer pathogenesis and treatment resistance through various mechanisms, including those mediated by insulin, leptin, adipokine, and aromatase signalling pathways, particularly in women. Furthermore, adiposity-related changes can influence tumour vascularity and inflammation in the tumour microenvironment, which can support tumour development and growth. Trials investigating non-pharmacological approaches to target the mechanisms driving obesity-mediated cancer pathogenesis are emerging and are necessary to better appreciate the interplay between malignancy, adiposity, diet and exercise. Diet, exercise and bariatric surgery are potential strategies to reverse the cancer-promoting effects of obesity; trials of these interventions should be conducted in a scientifically rigorous manner with dose escalation and appropriate selection of tumour phenotypes and have cancer-related clinical and mechanistic endpoints. We are only beginning to understand the mechanisms by which obesity effects cell signalling and systemic factors that contribute to oncogenesis. As the rates of obesity and cancer increase, we must promote the development of non-pharmacological lifestyle trials for the treatment and prevention of malignancy.

Obesity, Cancer, and Risk Reduction with Bariatric Surgery

The prevalence of noncommunicable diseases has increased dramatically in North America and throughout the world and is expected to continue increasing in coming years. Obesity has been linked to several types of cancers and is associated with increased morbidity and mortality following cancer diagnosis. Bariatric surgery has emerged as the prominent model to evaluate the effects of intentional weight loss on cancer incidence and outcomes. Current literature, comprising prospective cohort investigations, indicates site-specific reductions in cancer risk with select bariatric procedures. Future research is required to establish evidence-based indications for bariatric surgery in the context of cancer prevention.

The effect of bariatric surgery on breast cancer incidence and characteristics: A meta-analysis and systematic review

BACKGROUND

Obesity is a major risk factor for breast cancer. This study examines whether bariatric surgery affects breast cancer incidence in women with obesity compared to BMI-matched controls.

METHODS

EMBASE, MEDLINE, Web of Science, and CINAHL were searched. Primary studies on female breast cancer incidence after bariatric surgery were eligible.

RESULTS

11 studies were included (n = 1,106,939). The rate of cancer diagnosis was lower in the surgical group (0.54%) compared to control (0.84%; risk ratio (RR) 0.50, 95%CI 0.37-0.67, I² = 88%). The results were robust to sensitivity analyses for patient age and study size. Bariatric surgery was associated with increased risk of stage I cancer (RR 1.23, 95%CI 1.06-1.44) and reduced risk of stage III or IV cancer (RR 0.50, 95%CI 0.28-0.88). Hormone receptor characteristics were not affected.

CONCLUSIONS

Bariatric surgery is associated with reduced incidence and earlier stage at diagnosis of breast cancer in women with obesity compared to BMI-matched controls.

Impact of sex hormones dysregulation and adiposity on the outcome of postmenopausal breast cancer patients

Epidemiological studies demonstrated that, in postmenopausal women, high circulating levels of testosterone, especially when associated with weight gain, positively correlated with an increased risk of breast cancer because of the augmented production of oestrogen via testosterone aromatization in the adipose tissue. Besides, growing evidence suggests that sulfatase can increase the tissue concentration of bioactive estradiol through the reconversion of estrone sulfate, thus providing a favourable milieu for epithelial cells expressing the oestrogen receptor. In this review, we will discuss how the "obesity-insulin-testosterone" connection and the abnormal production of bioactive oestrogen - as a result of the conversion of the androgens by aromatase and the estrone reconversion by sulfatase-, may affect the response to hormone therapy and the outcome of postmenopausal breast cancer patients, and how a combined therapy including metformin, anti-inflammatory drugs, and aromatase/sulfatase inhibitors could successfully improve patient's outcome.

Simultaneous surgeries in bariatric surgery (literature review)

Based on the available publications, the article presents an analysis of the studies on the simultaneous implementation of cholecystectomy, ventral and paraesophageal hernia repair during a bariatric intervention. If there is a clinical picture of chronic calculous cholecystitis, simultaneous cholecystectomy is justified and does not lead to a significant increase in the number of complications. In the case of asymptomatic gallstones, the optimal tactics remains controversial, both a surgical treatment and observation are possible. In the absence of gallstone disease, all patients after the surgical correction of the excess weight are prescribed ursodeoxycholic acid, while performing preventive cholecystectomy is not recommended. A simultaneous ventral hernia repair is justified only for small defects ( 10 cm) of the anterior abdominal wall. If a paraesophageal hernia is detected in patients with morbid obesity, bariatric surgery may be combined with cruroraphy.

Microbiome, bile acids, and obesity: How microbially modified metabolites shape anti-tumor immunity

Bile acids (BAs) are known facilitators of nutrient absorption but recent paradigm shifts now recognize BAs as signaling molecules regulating both innate and adaptive immunity. Bile acids are synthesized from cholesterol in the liver with subsequent microbial modification and fermentation adding complexity to pool composition. Bile acids act on several receptors such as Farnesoid X Receptor and the G protein-coupled BA receptor 1 (TGR5). Interestingly, BA receptors (BARs) are expressed on immune cells and activation either by BAs or BAR agonists modulates innate and adaptive immune cell populations skewing their polarization toward a more tolerogenic anti-inflammatory phenotype. Intriguingly, recent evidence also suggests that BAs promote anti-tumor immune response through activation and recruitment of tumoricidal immune cells such as natural killer T cells. These exciting findings have redefined BA signaling in health and disease wherein they may suppress inflammation on the one hand, yet promote anti-tumor immunity on the other hand. In this review, we provide our readers with the most recent understanding of the interaction of BAs with the host microbiome, their effect on innate and adaptive immunity in health and disease with a special focus on obesity, bariatric surgery-induced weight loss, and immune checkpoint blockade in cancer.