A Randomized Trial Comparing the Effectiveness of Pre-test Genetic Counseling Using an Artificial Intelligence Automated Chatbot and Traditional In-person Genetic Counseling in Women Newly Diagnosed with Breast Cancer

BACKGROUND

Alternative service delivery models are critically needed to address the increasing demand for genetics services and limited supply of genetics experts available to provide pre-test counseling.

METHODS

We conducted a prospective randomized controlled trial of women with stage 0-III breast cancer not meeting National Comprehensive Cancer Network (NCCN) criteria for genetic testing. Patients were randomized to pre-test counseling with a Chatbot or a certified genetic counselor (GC). Participants completed a questionnaire assessing their knowledge of breast cancer genetics and a survey assessing satisfaction with their decision regarding pre-test counseling.

RESULTS

A total of 39 patients were enrolled and 37 were randomized to genetic counseling with an automated Chatbot or a GC; 19 were randomized to Chatbot and 18 to traditional genetic counseling, and 13 (38.2%) had a family member with breast cancer but did not meet NCCN criteria. All patients opted to undergo genetic testing. Testing revealed six pathogenic variants in five patients (13.5%): CHEK2 (n = 2), MSH3 (n = 1), MUTYH (n = 1), and BRCA1 and HOXB13 (n = 1). No patients had a delay in time-to-treatment due to genetic testing turnaround time, nor did any patients undergo additional risk reducing surgery. There was no significant difference in median knowledge score between Chatbot and traditional counseling (11 vs. 12, p = 0.09) or in median patient satisfaction score (30 vs. 30, p = 0.19).

CONCLUSION

Satisfaction and comprehension in patients with breast cancer undergoing pre-test genetic counseling using an automated Chatbot is comparable to in-person genetic testing. Utilization of this technology can offer improved access to care and a much-needed alternative for pre-test counseling.

Male Breast Cancer Patient and Surgeon Experience: The Male WhySurg Study

BACKGROUND

Little is known about the experience of the male breast cancer patient. Mastectomy is often offered despite evidence that breast-conserving surgery (BCS) provides similar outcomes.

METHODS

Two concurrent online surveys were distributed from August to October 2020 via social media to male breast cancer (MBC) patients and by email to American Society of Breast Surgeon members. The MBC patients were asked their opinions about their surgery, and the surgeons were asked to provide surgical recommendations for MBC patients.

RESULTS

The survey involved 63 MBC patients with a mean age of 62 years (range, 31-79 years). Five MBC patients (7.9 %) stated that their surgeon recommended BCS, but 54 (85.7 %) of the patients underwent unilateral, and 8 (12.7 %) underwent bilateral mastectomy. Most of the patients (n = 60, 96.8 %) had no reconstruction. One third of the patients (n = 21, 33.3 %) felt somewhat or very uncomfortable with their appearance after surgery. The response rate was 16.5 % for the surgeons. Of the 438 surgeons who answered the survey, 298 (73.3 %) were female, 215 (51.7 %) were fellowship-trained, and 244 (58.9 %) had been practicing for 16 years or longer. More than half of surgeons (n = 259, 59.1 %) routinely offered BCS to eligible men, and 180 (41.3 %) stated they had performed BCS on a man with breast cancer. Whereas 89 (20.8 %) of the surgeons stated that they routinely offer reconstruction to MBC patients, 87 (20.3 %) said they do not offer reconstruction, 96 (22.4 %) said they offer it only if the patient requests it, and 157 (36.6 %) said they never consider it as an option.

CONCLUSIONS

The study found discordance between MBC patients' satisfaction with their surgery and surgeon recommendations and experience. These data present an opportunity to optimize the MBC patient experience.

Lapses in breast cancer screening for highly penetrant mutation carriers during pregnancy and lactation

BACKGROUND AND OBJECTIVES

Screening for breast cancer in highly penetrant mutation carriers during pregnancy and lactation is challenging and consensus guidelines are lacking. This study evaluates the lapse in screening and the interval pregnancy-associated breast cancer rate.

METHODS

A single-institution retrospective cohort study of pregnant and lactating patients with known pathogenic germline mutations was performed. Lapse in screening was defined as the interval between the last screening imaging exam obtained before last menstrual period and the subsequent screening imaging.

RESULTS

Out of 685 patients, 42 had 1-3 evaluable pregnancies (54 total - 28 managed in High Risk Breast Clinic and 26 by OB/GYN). Mutations were observed in patients in BRCA1 (49%), BRCA2 (36%), CDH1 (5%), CHEK2 (2%), ATM (2%), NF1 (3%), and MSH2 (3%). The average screening lapse was 25 [19, 30] months for patients followed in the High Risk Clinic versus 32.5 [21, 65.75] months for patients followed with Routine Care (p = 0.035). We identified three cases of pregnancy-associated breast cancer (interval cancer rate 6%).

CONCLUSIONS

Patients with highly penetrant mutations are at risk for the development of interval pregnancy-associated breast cancer. Development of consistent screening guidelines and adherence to those guidelines is needed for this patient population.

Anastomotic leak following interval debulking surgery with or without hyperthermic intraperitoneal chemotherapy in women with advanced epithelial ovarian Cancer

OBJECTIVE(S)

To evaluate the incidence and associated risk factors for anastomotic failure following interval debulking surgery (IDS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) in women with advanced ovarian cancer.

METHODS

We performed a retrospective cohort study in women with stage III/IV high-grade ovarian cancer treated with neoadjuvant chemotherapy followed by IDS with colorectal resection and HIPEC from 2017 to 2020. These patients were compared to a historical control cohort who underwent IDS with colorectal resection without HIPEC from 2009 to 2016. Data was collected for demographics, surgical variables, and perioperative outcomes. The univariate analysis compared progression-free survival and overall survival.

RESULTS

61 women were identified; 21 (34.4%) underwent IDS with HIPEC from 2017 to 2020, and 40 underwent IDS alone from 2009 to 2016. None of the patients who had IDS with HIPEC had protective ileostomy, compared to 10.0% of those who received had IDS alone (n = 4)(p = 0.29). The cumulative incidence of anastomotic leak rate was 8.2% (n = 5). There was no significant difference in anastomotic leak rate for women who underwent IDS with HIPEC (9.5%, n = 2) versus without HIPEC (7.5%, n = 3) (p = 0.99). While there was no difference in PFS (12.2 vs. 13.3 months, log-rank p = 0.31), OS (9.4 vs. 40.6 months, log-rank p = 0.013) was significantly decreased following postoperative anastomotic leak.

CONCLUSIONS

In this retrospective series of women with advanced ovarian cancer, HIPEC was not associated with increased risk for anastomotic leak at the time of IDS with colorectal resection and reanastomosis. While further study is needed, HIPEC alone should not preclude colorectal resection or dictate practices for colonic diversion in IDS.

Modified frailty index predicts postoperative complications in women with gynecologic cancer undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

OBJECTIVE(S)

To evaluate the impact of frailty on postoperative complications following cytoreductive surgery (CRS) with hyperthermic intra-peritoneal chemotherapy (HIPEC) in women with advanced or recurrent gynecologic cancer.

METHODS

An IRB-approved single-institution prospective registry was queried for women who underwent CRS with HIPEC for advanced or recurrent gynecologic cancer from 1/1/2014-12/31/2020. Frailty was defined as a modified Frailty Index (mFI) score of ≥2. Logistic regression was used to assess the impact of mFI upon the rate of moderate or higher (≥ grade 2) Accordion postoperative complications.

RESULTS

Of 141 women, 81.6% (n = 115) were non-frail with mFI of 0-1 and 18.4% (n = 26) were frail with mFI ≥2. The incidence of ≥ grade 2 complications was 21.2% (n = 14) for mFI = 0, 26.5% (n = 13) for mFI = 1, 64.7% (n = 11) for mFI = 2 and 100.0% (n = 9) for patients with mFI ≥3. The incidence of re-operation (1.7% vs. 11.5%, p = 0.044), ICU admission (13.2% vs. 34.6%, p = 0.018), acute kidney injury (6.3% vs. 30.8%, p = 0.001), and respiratory failure (0.9% vs. 19.2%, p < 0.001) were significantly lower amongst non-frail vs. frail women. On multivariable analysis, mFI ≥2 was associated with significantly increased ≥ grade 2 complications versus mFI of 0-1 (OR 9.4, 95% CI 3.3, 26.4, p < 0.001). Age (OR 1.04, 95% CI 1.00, 1.09, p = 0.07), surgical indication (recurrent vs. primary) (OR 0.71, 95% CI 0.30, 1.7, p = 0.44) and Surgical Complexity Score of Intermediate or High vs. Low (OR 1.5, 95% CI 0.67, 3.5, p = 0.31) were not associated with ≥grade 2 complications.

CONCLUSIONS

Frailty, defined by the modified frailty index, is predictive of ≥grade 2 postoperative complications following CRS with HIPEC in women with gynecologic cancer. Frailty screening before CRS with HIPEC may assist patient selection and improve postoperative outcomes.

Perioperative outcomes of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in elderly women with epithelial ovarian cancer: analysis of a prospective registry

OBJECTIVE

To evaluate perioperative outcomes in elderly versus non-elderly women with advanced or recurrent epithelial ovarian cancer undergoing surgery with hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

A single-institution prospective registry was analyzed for women with ovarian cancer who underwent surgery with HIPEC from January 2014 to December 2020. Elderly age was defined as ≥65 years at surgery. Complications were defined according to the Accordion scale. Univariate and multivariable analysis was used to compare progression-free survival and overall survival.

RESULTS

Of 127 women who underwent surgery with HIPEC, 33.1% (n=42) were ≥65 and 17.3% (n=22) were ≥70 years old. The median age for non-elderly and elderly patients were 55.7±8.3 versus 72.0±5.4 years, respectively (p<0.001). The majority of non-elderly versus elderly patients underwent HIPEC at the time of interval cytoreductive surgery following neoadjuvant chemotherapy (52.9% vs 73.8%, p=0.024). There were no differences in moderate (15.3% vs 26.2%) or severe postoperative complications (10.6% vs 11.9%, p=0.08), acute kidney injury (7.1% vs 16.7%, p=0.12), and length of stay (5.0 vs 5.0 days, p=0.56) for non-elderly versus elderly patients. With a median follow-up of 20 months (95% CI 9.1 to 32.7 months), there was no difference in progression-free survival (18.8 vs 15.7 months, p=0.75) or overall survival (61.6 months vs not estimable, p=0.72) for non-elderly versus elderly patients. Comparing patients 65-69 versus ≥70 years, progression-free survival (33.0 vs 12.5 months, p=0.002) was significantly improved in patients aged 65-69, without difference in overall survival (not estimable vs 36.0 months, p=0.91). On multivariable analysis, age ≥65 did not impact progression-free survival (p=0.74).

CONCLUSIONS

In this prospective registry of women with ovarian cancer, perioperative morbidity is not increased for non-elderly versus elderly patients following surgery with HIPEC. While age should not exclude patients from surgery with HIPEC, additional research is needed regarding oncologic benefits in elderly women.

Patterns of recurrence in women with advanced and recurrent epithelial ovarian cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

OBJECTIVE(S)

To identify recurrence patterns and outcomes in women with advanced or recurrent epithelial ovarian cancer (EOC) after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

METHODS

This is an IRB-approved single-institution cohort study of women who underwent CRS+HIPEC for advanced or recurrent EOC followed in a prospective registry from 1/12/2014-3/1/2020. Recurrence locations were defined as pelvic, upper abdominal (UA) and/or extra-peritoneal (EP). Univariate analysis assessed associations between recurrence location, progression-free survival (PFS), and overall survival (OS).

RESULTS

In total, 92 women with EOC underwent interval (56.5%; n=52) or recurrent CRS+HIPEC (43.5%; n=40). For interval CRS+HIPEC, recurrence locations were pelvic in 50.0% (n=15), UA in 23.3% (n=7) and EP in 56.7% (n=17); 40.0% (n=12) were EP alone. Similarly, for recurrent CRS+HIPEC, recurrence locations were pelvic (22.5%, n=9), UA (5.0%, n=2) and EP (60.0%, n=24); 66.7% (n=20) were EP alone. For both interval and recurrent CRS+HIPEC, median PFS was 10.5 vs. 13.0 months for pelvic and UA vs. EP only recurrences (p=0.02). Similarly, median OS was 29.2 months for pelvic and UA and not reached for EP only (p=0.05). For interval CRS+HIPEC, there was no difference in median PFS (10.6 vs. 11.7 months, p=0.68) and OS (27.1 vs. 24.8 months, p=0.96) for pelvic and UA vs EP alone. However, for recurrent CRS+HIPEC, pelvic and UA sites of recurrence were associated with reduced PFS (10.0 vs. 18.1 months, p=0.03) and OS (33.6 months vs. not reached, p=0.02) vs. EP only.

CONCLUSIONS

In women with advanced or recurrent EOC undergoing CRS+HIPEC, one-half of patients experience their first recurrence outside of the peritoneal cavity. Providers must be aware of the risk of EP failure in patients treated with CRS+HIPEC.

Impact of intra-operative factors upon peri-operative outcomes in women undergoing hyperthermic intraperitoneal chemotherapy for gynecologic cancer

OBJECTIVES

To evaluate the incidence of intra-operative metabolic and electrolyte abnormalities and subsequent impact on peri-operative outcomes in women with gynecologic cancer undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC).

METHODS

An IRB-approved single institution retrospective cohort study was performed in women with gynecologic cancer who underwent CRS + HIPEC. Patient demographics, intra-operative electrolyte and metabolic values and peri-operative outcomes were recorded. To assess the association of pH and lactate upon post-operative outcomes, patients were divided in four quartiles for both variables and univariate analysis was performed.

RESULTS

100 consecutive women who underwent CRS + HIPEC from 2017 to 2020 were identified. Intra-operative blood transfusion and pressor support were required in 40% and 86%, respectively. The rate of ICU admission was 17%. Longer operative time (7.0 vs. 5.3 h, p = 0.002), increased blood loss (400.0 vs. 200.0 mL, p = 0.02) and transfusion (70.6% vs. 34.1%, p = 0.005) were associated with ICU admission. Compared to patients in the highest quartile of pH, lower median pH, (7.211 vs. 7.349, p < 0.001) was associated with increased rates of ICU admission, prolonged intubation (36.0% vs. 0.0%, p < 0.05, respectively) and any post-operative complication (72.0% vs. 28.0%, p = 0.01). Similarly, need for prolonged intubation (40% vs. 0%, p = 0.04) and VTE (13.0% vs. 0%, p = 0.01) were increased in women with the highest quartile of lactate levels compared to the lowest (4.7 vs 1.9, p < 0.001).

CONCLUSIONS

Intra-operative acidosis is associated with higher incidence of ICU admission and peri-operative complications following CRS + HIPEC in women with gynecologic cancer. These data support the importance of adequate intra-operative resuscitation and timely correction of hemodynamic and metabolic abnormalities.

Assessing feasibility and perioperative outcomes with minimally invasive surgery compared with laparotomy for interval debulking surgery with hyperthermic intraperitoneal chemotherapy for advanced epithelial ovarian cancer

Objective

To determine peri-operative outcomes in women with advanced epithelial ovarian cancer (EOC) undergoing interval debulking surgery (IDS) with hyperthermic intraperitoneal chemotherapy (HIPEC) via minimally invasive interval debulking surgery (MIS) or laparotomy (LAP).

Methods

A single institution, retrospective cohort study was performed in women with EOC who underwent IDS with HIPEC from 2017 to 2019 via MIS or LAP. Peri-operative outcomes were compared using univariate analysis.

Results

In total, 50 eligible women were identified; ten (20.0%) underwent MIS + HIPEC and 40 (80.0%) LAP + HIPEC. The median age of patients in the MIS group was 71.1 vs. 64.2 years in LAP (p = 0.031). There was no significant difference in pre-operative complete radiographic response following NACT (p = 0.18). Notably, there was no difference in the rate of R0 resection (70.0% vs. 77.5%; p = 0.39). There was no significant difference in ICU admission, estimated blood loss, operative time, or use of vasopressors between the cohorts. Similarly, there was no difference in 30-day adverse events for MIS vs. LAP, but length of stay was decreased for those who underwent minimally invasive procedures (3 vs. 4 days, p = 0.016). Time to initiation of chemotherapy following surgery was not significantly different between groups (26.2 days vs 32.0 days, p = 0.090). With median follow-up of 15.1 months, there was no difference in recurrence free survival (median 15.0 vs 17.2 months log-rank, p = 0.30) for MIS vs. LAP.

Conclusions

In this retrospective cohort study, we demonstrate that in women with advanced EOC, HIPEC with MIS at the time of IDS following NACT is feasible. Our institutional experience demonstrates similar rates of R0 cytoreduction, compared to LAP. An MIS approach should not prevent surgeons from utilizing HIPEC where indicated for management of advanced EOC.

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When comparing MIS and LAP at time of HIPEC, no differences are observed in adverse perioperative outcomes.

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MIS was associated with shorter hospitalization and with no significant difference in the rate of R0 resections.

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Patient candidacy for an MIS IDS should not prevent surgeons from utilizing HIPEC in appropriate candidates.

Impact of antibiotic treatment during platinum chemotherapy on survival and recurrence in women with advanced epithelial ovarian cancer

OBJECTIVE(S)

To determine whether antibiotic treatment (ABX) during platinum chemotherapy (PC) for epithelial ovarian cancer (EOC) impacts progression-free survival (PFS) and overall survival (OS).

STUDY DESIGN

Retrospective single institution cohort study in women with newly diagnosed stage III/IV EOC (n = 424) who underwent cytoreductive surgery (CRS) and PC from 2009 to 2015. ABX for >48 h, including ABX against gram-positive (anti-G + ABX) bacteria were recorded. The impact of ABX on PFS and OS was assessed using univariate and multivariable Cox regression models.

RESULTS

Of 424 eligible women, 34.7% (n = 147) received ABX, with 11.3% (n = 48) treated with anti-G + ABX. ABX decreased PFS (17.4 vs. 23.1 months, HR 1.50, 95% CI 1.20-1.88, p < 0.001) and OS (45.6 vs. 62.4 months, HR 1.63, 95% CI 1.27-2.08, p < 0.001) compared to no ABX. Similarly, anti-G + ABX worsened PFS (16.5 vs. 23.1 months; HR 1.85, 95% CI 1.33-2.55) and OS (35.0 vs. 62.4 months; HR 2.12, 95% CI 1.50-3.0, p < 0.001). On multivariable analysis, all ABX and anti-G + ABX significantly worsened PFS (HR 1.31, 95% CI 1.04-1.65, p = 0.02), (HR 1.50, 95% CI 1.07-2.10, p = 0.02) and OS (HR 1.52, 95% CI 1.18-1.96, p = 0.001), (HR 1.83, 95% CI 1.27-2.62, p = 0.001) respectively. Increased Clavien Dindo score was associated with worsened PFS (1-2 - HR 1.52, 95% CI 1.14-2.03, p = 0.004; 3-4 - HR 1.86, 95% CI 1.27-2.72, p = 0.001) but not OS (1/2 - HR 1.35, 95% CI 0.97-1.88, p = 0.08; 3/4 - HR 1.53, 95% CI 1.00-2.34, p = 0.05); residual disease (p < 0.05) and neoadjuvant chemotherapy (p < 0.001) were associated with worse PFS and OS.

CONCLUSION(S)

In this retrospective cohort study of women with advanced EOC undergoing PC, ABX treatment was associated with decreased PFS and OS. Mechanistic studies are needed to investigate the negative impact of ABX upon PC response in EOC.

Perioperative Interventions to Minimize Blood Loss at the Time of Hysterectomy for Uterine Leiomyomas: A Systematic Review and Meta-analysis

STUDY OBJECTIVE

Hysterectomy for uterine leiomyoma(s) is associated with significant morbidity including blood loss. A systematic review and meta-analysis was conducted to identify nonhormonal interventions, perioperative surgical interventions, and devices to minimize blood loss at the time of hysterectomy for leiomyoma.

DATA SOURCES

Librarian-led search of Embase, MEDLINE, Web of Science, Scopus, Cumulative Index to Nursing and Allied Health Literature, and Cochrane databases from 1946 to 2018 with hand-guided updates.

METHODS OF STUDY SELECTION

Included studies reported on keywords of hysterectomy, leiomyoma, and operative blood loss/postoperative hemorrhage/uterine bleeding/metrorrhagia/hematoma. The review excluded a comparison of route of hysterectomy, morcellation, vaginal cuff closure, hormonal medications, vessel sealing devices for vaginal hysterectomy, and case series with <10 patients.

TABULATION, INTEGRATION, AND RESULTS

Surgical blood loss, postoperative hemoglobin (Hb) drop, hemorrhage, transfusion, and major and minor complications were analyzed and aggregated in meta-analyses for comparable studies in each category. A total of 2016 unique studies were identified, 33 of which met the inclusion criteria, and 22 were used for quantitative synthesis. The perioperative use of misoprostol in abdominal hysterectomy (AH) was associated with a lower postoperative Hb drop (0.59 g/dL; 95% confidence interval [CI], 0.39-0.79; p < .01) and blood loss (-96.43 mL; 95% CI, -153.52 to -39.34; p < .01) compared with placebo. Securing the uterine vessels at their origin in laparoscopic hysterectomy (LH) was associated with decreased intraoperative blood loss (-69.07 mL; 95% CI, -135.20 to -2.95; p = .04) but no significant change in postoperative Hb (0.24 g/dL; 95% CI, -0.31 to 0.78; p = .39) compared with securing them by the uterine isthmus. Uterine artery ligation in LH before dissecting the ovarian/utero-ovarian vessels was associated with lower surgical blood loss compared with standard ligation (-27.72 mL; 95% CI, -35.07 to -20.38; p < .01). The postoperative Hb drop was not significantly different with a bipolar electrosurgical device versus suturing in AH (0.26 g/dL; 95% CI, -0.19 to 0.71; p = .26). There was no significant difference between an electrosurgical bipolar vessel sealer (EBVS) and conventional bipolar electrosurgical devices in the Hb drop (0.02 g/dL; 95% CI, -0.15 to 0.20; p = .79) or blood loss (-50.88 mL; 95% CI, -106.44 to 4.68; p = .07) in LH. Blood loss in LH was not decreased with the LigaSure (Medtronic, Minneapolis, MN) impedance monitoring EBVS compared with competing EBVS systems monitoring impedance or temperature (2.00 mL; 95% CI, -8.09 to 12.09; p = .70). No significant differences in hemorrhage, transfusion, or major complications were noted for all interventions.

CONCLUSION

Perioperative misoprostol in AH led to a reduction in surgical blood loss and postoperative Hb drop (moderate level of evidence by Grading of Recommendations, Assessment, Development and Evaluation guidelines) although the clinical benefit is likely limited. Remaining interventions, although promising, had at best low-quality evidence to support their use at this time. Larger and rigorously designed randomized trials are needed to establish the optimal set of perioperative interventions for use in hysterectomy for leiomyomas.

Alteration of Mammary Gland Development and Gene Expression by In Utero Exposure to Cadmium

Environmental exposure to estrogens and estrogen like contaminants during early development is thought to contribute to the risk of developing breast cancer primarily due to an early onset of puberty; however, exposure during key developing windows may also influence the risk of developing the disease. The goal of this study was to ask whether in utero exposure to the metalloestrogen cadmium alters mammary gland development due to acceleration of puberty onset or to an effect on early development of the mammary gland. The results show that, in addition to advancing the onset of puberty, in utero exposure to the metalloestrogen cadmium altered mammary gland development prior to its effect on puberty onset. In utero exposure resulted in an expansion of the number of mammosphere-forming cells in the neonatal mammary gland and an increase in branching, epithelial cells, and density in the prepubertal mammary gland. In the postpubertal mammary gland, there was a further expansion of the mammary stem/progenitor cell population and overexpression of estrogen receptor-alpha (ERα) that was due to the overexpression and altered regulation of the ERα transcripts derived from exons O and OT in response to estradiol. These results suggest that in utero exposure to cadmium increases stem/progenitor cells, cell density, and expression of estrogen receptor-alpha that may contribute to the risk of developing breast cancer.

The transcription factor BACH2 promotes tumor immunosuppression

The immune system has a powerful ability to recognize and kill cancer cells, but its function is often suppressed within tumors, preventing clearance of disease. Functionally diverse innate and adaptive cellular lineages either drive or constrain immune reactions within tumors. The transcription factor (TF) BACH2 regulates the differentiation of multiple innate and adaptive cellular lineages, but its role in controlling tumor immunity has not been elucidated. Here, we demonstrate that BACH2 is required to establish immunosuppression within tumors. Tumor growth was markedly impaired in Bach2-deficient mice and coincided with intratumoral activation of both innate and adaptive immunity. However, augmented tumor clearance in the absence of Bach2 was dependent upon the adaptive immune system. Analysis of tumor-infiltrating lymphocytes from Bach2-deficient mice revealed high frequencies of rapidly proliferating effector CD4+ and CD8+ T cells that expressed the inflammatory cytokine IFN-γ. Effector T cell activation coincided with a reduction in the frequency of intratumoral Foxp3+ Tregs. Mechanistically, BACH2 promoted tumor immunosuppression through Treg-mediated inhibition of intratumoral CD8+ T cells and IFN-γ. These findings demonstrate that BACH2 is a key component of the molecular program of tumor immunosuppression and identify therapeutic targets for the reversal of immunosuppression in cancer.

Cish actively silences TCR signaling in CD8+ T cells to maintain tumor tolerance

Palmer et al. find that Cish, a member of the SOCS family, is induced by TCR stimulation in CD8⁺ T cells and inhibits their functional avidity against tumor. The authors uncover a novel mechanism of suppression for a SOCS member.

Improving the functional avidity of effector T cells is critical in overcoming inhibitory factors within the tumor microenvironment and eliciting tumor regression. We have found that Cish, a member of the suppressor of cytokine signaling (SOCS) family, is induced by TCR stimulation in CD8⁺ T cells and inhibits their functional avidity against tumors. Genetic deletion of Cish in CD8⁺ T cells enhances their expansion, functional avidity, and cytokine polyfunctionality, resulting in pronounced and durable regression of established tumors. Although Cish is commonly thought to block STAT5 activation, we found that the primary molecular basis of Cish suppression is through inhibition of TCR signaling. Cish physically interacts with the TCR intermediate PLC-γ1, targeting it for proteasomal degradation after TCR stimulation. These findings establish a novel targetable interaction that regulates the functional avidity of tumor-specific CD8⁺ T cells and can be manipulated to improve adoptive cancer immunotherapy.