Detection of Residual Peritoneal Metastases Following Cytoreductive Surgery Using Pegsitacianine, a pH-Sensitive Imaging Agent: Final Results from a Phase II Study

BACKGROUND

For patients with peritoneal carcinomatosis, extent of disease and completeness of cytoreductive surgery (CRS) are major prognostic factors for long-term survival. Assessment of these factors could be improved using imaging agents. Pegsitacianine is a pH-sensitive polymeric micelle conjugated to the fluorophore indocyanine green. The micelle disassembles in acidic microenvironments, such as tumors, resulting in localized fluorescence unmasking. We assessed the utility of pegsitacianine in detecting residual disease following CRS.

PATIENTS AND METHODS

NCT04950166 was a phase II, non-randomized, open-label, multicenter US study. Patients eligible for CRS were administered an intravenous dose of pegsitacianine at 1 mg/kg 24-72 h before surgery. Following CRS, the peritoneal cavity was reexamined under near-infrared (NIR) illumination to evaluate for fluorescent tissue. Fluorescent tissue identified was excised and evaluated by histopathology. The primary outcome was the rate of clinically significant events (CSE), defined as detection of histologically confirmed residual disease excised with pegsitacianine or a revision in the assessment of completeness of CRS. Secondary outcomes included acceptable safety and pegsitacianine performance.

RESULTS

A total of 53 patients were screened, 50 enrolled, and 40 were evaluable for CSE across six primary tumor types. Residual disease was detected with pegsitacianine in 20 of 40 (50%) patients. Pegsitacianine showed high sensitivity and was well tolerated with no serious adverse events (SAEs). Transient treatment-related, non-anaphylactic infusion reactions occurred in 28% of patients.

CONCLUSIONS

Pegsitacianine was well tolerated and facilitated the recognition of occult residual disease following CRS. The high rate of residual disease detected suggests that the use of pegsitacianine augmented surgeon assessment and performance during CRS.

Rates of high-risk screening prior to a breast cancer diagnosis in patients under age 40

BACKGROUND

NCCN Guidelines recommend screening young women with an increased breast cancer risk (>20 ​% lifetime risk). We sought to evaluate our institutional rates of high-risk screening in young breast cancer patients prior to their diagnoses."

METHODS

A single-institution retrospective review (2013-2018) was performed investigating risk scores (Tyrer-Cuzick model) and characteristics of breast cancer patients (age <40 ​y) prior to diagnosis.

RESULTS

92 breast cancer patients age <40 ​y were identified (average age 34.5). Only 3.3 ​% (n ​= ​3) underwent appropriate screening, despite 35.8 ​% meeting high-risk criteria. Nearly all patients underwent genetic testing (98.9 ​%) with pathogenic mutations identified in 36.5 ​%, including 15.3 ​% with BRCA1/2 mutations.

CONCLUSIONS

This analysis highlights a significant discrepancy between those meeting criteria for high-risk screening and those who underwent appropriate screening. We identified that this cohort carries significant genetic burden. Future analysis should investigate these findings on a broader scale and strategies to improve screening.

Distance Traveled and Disparities in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

The impact of distance traveled on cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) outcomes needs further investigation.

METHODS

This retrospective study reviewed a prospectively managed single-center CRS/HIPEC 1992-2022 database. Zip codes were used to calculate distance traveled and to obtain data on income and education via census data. Patients were separated into three groups based on distance traveled in miles (local: ≤50 miles, regional: 51-99 miles, distant: ≥100 miles). Descriptive statistics, Kaplan-Meier method, and Cox regression were performed.

RESULTS

The 1614 patients in the study traveled a median distance of 109.5 miles (interquartile range [IQR], 53.36-202.29 miles), with 23% traveling locally, 23.9% traveling regionally, and 53% traveling distantly. Those traveling distantly or regionally tended to be more white (distant: 87.8%, regional: 87.2%, local: 83.2%), affluent (distant: $61,944, regional: $65,014, local: $54,390), educated (% without high school diploma: distant: 10.6%, regional: 11.5%, local: 13.0%), less often uninsured (distant: 2.3%, regional: 4.6%, local: 5.2%) or with Medicaid (distant: 3.3%, regional: 1.3%, local: 9.7%). They more often had higher Peritoneal Carcinomatosis Index (PCI) scores (distant: 15.4, regional: 15.8, local: 12.7) and R2 resections (distant: 50.3%, regional: 52.2%, local: 40.5%). Median survival did not differ between the groups, and distance traveled was not a predictor of survival.

CONCLUSION

More than 50% of the patients traveled farther than 100 miles for treatment. Although regionalization of CRS/HIPEC may be appropriate given the lack of survival difference based on distance traveled, those who traveled further had fewer health care disparities but higher PCI scores and more R2 resections, which raises concerns about access to care for the underserved, time to treatment, and surgical quality.

Quality-of-Life Outcomes for Patients Taking Opioids and Psychotropic Medications Before Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

The impact of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) on quality of life (QoL) for patients taking opioids and psychotropic medications preoperatively is unclear.

METHODS

This study retrospectively reviewed a CRS-HIPEC single-center prospectively maintained database for 2012-2016. Demographics and clinical data on opioids/psychotropic medication use were collected via chart review. The study collected QoL outcomes at baseline, then 3, 6, and 12 months postoperatively via the Center for Epidemiologic Studies Depression Scale (CES-D), Brief Pain Inventory, Functional Assessment of Cancer Therapy, and 36-Item Short-Form Health Survey. Differences in QoL between the groups were calculated using repeated measures analysis of variance regression. Descriptive statistics and Kaplan-Meier analyses were performed.

RESULTS

Of 388 patients, 44.8% were taking opioids/psychotropic medications preoperatively. At baseline, those taking opioids/psychotropic medications preoperatively versus those not taking these medications had significantly worse QoL. By 1 year postoperatively, the QoL measures did not differ significantly except for emotional functioning (e.g., no medications vs. opioids/psychotropic medications: CES-D, 5.6 vs. 10.1). Median survival did not differ significantly (opioids/psychotropic medications vs. no medications: 52.3 vs. 60.6 months; p = 0.66). At 1 year after surgery, a greater percentage of patients were taking opioids, psychotropic medications, or both than at baseline (63.2% vs. 44.8%; p < 0.001).

CONCLUSION

Despite worse baseline QoL, patients who took opioids/psychotropic medications had QoL scores 1 year postoperatively similar to the scores of those who did not except in the emotional domains. These data point to the potential utility of a timed psychosocial intervention to enhance emotional adaptation and further support the role of CRS-HIPEC in improving QoL.

Pivotal Role of Genetic Counselors in the Uptake of Germline Genetic Testing in Non-Metastatic Breast Cancer and the Impact of Testing on Surgical Decision Making

BACKGROUND

Genetic testing is increasingly utilized in breast cancer patients; however, testing rates remain low. We aimed to evaluate the rate of genetic testing at a tertiary academic medical center utilizing a multidisciplinary clinic model including genetic counselor.

METHODS

A single-center retrospective chart review was performed on a cohort of newly diagnosed breast cancer patients from January 2018 through February 2019. Patients were reviewed for genetic screening eligibility, consultation with a genetic counselor, and test results.

RESULTS

Final analysis included 426 patients. 261 (61.3%) were found to meet National Comprehensive Cancer Network guidelines for genetic testing, of which 178 patient (68.2%) underwent testing and 32 patients (12.3%) declined testing. Of the 165 not eligible for testing, 5 patients were tested. A total of 183 patients underwent testing and 116 (63.4%) had a negative result, 17 (9.3%) were positive for at least one gene mutation and 50 (27.3%) were identified to have a variant of unknown significance (VUS). There was a positive association between those patients who met with a genetic counselor and eligibility for testing (OR 31.1, 95% CI 16.0-60.5).

CONCLUSIONS

Genetic testing result has become an increasingly important factor when defining optimal surgical treatment for breast cancer patients. Increasing the availability of genetic consultation for breast cancer patients can improve testing rates and patient selection.

Does Preoperative MRI Reduce Positive Margins after Breast-Conserving Surgery?

BACKGROUND

Breast-conserving surgery (BCS) is a mainstay for breast cancer management, and obtaining negative margins is critical. Some have advocated for the use of preoperative magnetic resonance imaging (MRI) in reducing positive margins after BCS. We sought to determine whether preoperative MRI was associated with reduced positive margins.

PATIENTS AND METHODS

The SHAVE/SHAVE2 trials were multicenter trials in ten US centers with patients with stage 0-3 breast cancer undergoing BCS. Use of preoperative MRI was at the discretion of the surgeon. We evaluated whether or not preoperative MRI was associated with margin status prior to randomization regarding resection of cavity with shave margins.

RESULTS

A total of 631 patients participated. Median age was 64 (range 29-94) years, with a median tumor size of 1.3 cm (range 0.1-9.3 cm). Patient factors included 26.1% of patients (165) had palpable tumors, and 6.5% (41) received neoadjuvant chemotherapy. Tumor factors were notable for invasive lobular histology in 7.0% (44) and extensive intraductal component (EIC) in 32.8% (207). A preoperative MRI was performed in 193 (30.6%) patients. Those who underwent preoperative MRI were less likely to have a positive margin (31.1% versus 38.8%), although this difference was not statistically significant (p = 0.073). On multivariate analysis, controlling for patient and tumor factors, utilization of preoperative MRI was not a significant factor in predicting margin status (p = 0.110). Rather, age (p = 0.032) and tumor size (p = 0.040) were the only factors associated with margin status.

CONCLUSION

These data suggest that preoperative MRI is not associated margin status; rather, patient age and tumor size are the associated factors.

Cisplatin exhibits superiority over MMC as a perfusion agent in a peritoneal mesothelioma patient specific organoid HIPEC platform

Peritoneal mesothelioma (PM) is a rare malignancy with poor prognosis, representing about 10-15% of all mesothelioma cases. Herein we apply PM patient-derived tumor organoids (PTOs) in elucidating personalized HIPEC responses to bypass rarity of disease in generating preclinical data. Specimens were obtained from PM patients undergoing cytoreductive surgery with HIPEC. PTOs were fabricated with tumor cells suspended in ECM-hydrogel and treated with HIPEC regimen parameters. Viability and characterization analyses were performed post-treatment. Treatment efficacy was defined as ≥ 50% viability reduction and p < 0.05 compared to controls. From October 2020 to November 2022, 17 tumors from 7 patients were biofabricated into organoids, with 16/17 (94.1%) sites undergoing comparative 37° and 42° treatments with cisplatin and mitomycin C (MMC). Hyperthermic cisplatin and MMC enhanced cytotoxicity which reduced treatment viability by 25% and 22%, respectively, compared to normothermia. Heated cisplatin displayed the greatest cytotoxicity, with efficacy in 12/16 (75%) tumors and an average viability of 38% (5-68%). Heated MMC demonstrated efficacy in 7/16 (43.8%) tumors with an average treatment viability of 51% (17-92.3%). PTOs fabricated from distinct anatomic sites exhibited site-specific variability in treatment responses. PM PTOs exhibit patient and anatomic location treatment responses suggestive of underlying disease clonality. In PM organoids cisplatin is superior to MMC in HIPEC.

Abstract 164: Development of a living biobank of breast cancer organoids

Introduction: Breast cancer is one of the most frequently diagnosed cancers among women, with a high mortality rate. More than 20 different subtypes of breast cancer are identified. Advancement in patient-derived organoid technology makes it possible to preserve cellular, structural, and tissue microenvironment, which mimics the tissue in vivo. The present study aims to develop a cryopreserved (living) tumor biobank from patient-derived tumor breast tissues. Eventually, biobank organoids will be used to test treatment options outside of patients, in a dish, and provide information on what treatments the patient responds to.

Method: Patient-derived organoids (PDOs) were bio-fabricated using an unsorted tumor and normal cell suspension in a collagen-based hydrogel. Immune-enhanced tumor organoids (iTOs) were also bio-fabricated using patient-matched PMBCs and tumor cells. Breast cancer living biobanks were developed by freezing organoids in cryopreservation solutions and reestablishing them in growth media compatible with breast organoids. Histological staining for hormone receptors and Her2 receptor markers was performed. Organoids were cultured for seven days, followed by treatment with chemotherapy (Paclitaxel, Doxorubicin, and Sulphonamide) and immunotherapy (Nivolumab, Pembrolizumab, and Atezolizumab), and assessed for cell viability.

Results: H&E staining showed the characteristics of the breast tissue with well-defined acini. In tumor organoids, acini were somewhat perturbed compared to normal breast organoids. Immunofluorescence staining showed the expression of breast biomarkers, including EGF receptor 2 (HER2), Progesterone receptor (PR), and Estrogen receptor (ER). Zona occludin 2 and keratin 19 expression in luminal cells and expression of Keratin 14 and P63 in basal cells, suggesting correct polarization in the organoids. Immunofluorescence staining of iTOs, with T cell markers including CD3, CD4, and CD8, indicated that immune cells remained viable in the iTOs. Drug responses to Doxorubicin, Paclitaxel, Sulphonamide and a combination of Doxorubicin-Paclitaxel showed significant inhibition of cell growth in normal and tumor organoids (p&lt; 0.04). Treatment of breast iTOs showed moderate responses to nivolumab (n=11) and pembrolizumab (n=5), with a 63%-100% efficacy (P &lt; 0.05) respectively. No responses were observed for Atezolizumab (n=5). Drug responses of biobank organoids showed comparable drug sensitivities to their fresh, non-frozen counterparts, suggesting that biobank organoids retain physiological relevant information and can be used for testing new drug therapies.

Conclusion: Breast cancer organoids recapitulate the histological features of breast tissue in culture and respond to chemotherapy and immunotherapy. In the future, patient-derived breast tumor organoids can be cryopreserved and serve as living biobanks to provide a platform for personalized medicine.

Citation Format: Nadeem Wajih, Richard Erali, Edward A. Levine, Konstantinos Votanopoulos, Shay Soker. Development of a living biobank of breast cancer organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 164.

Exposure to Neoadjuvant Oxaliplatin-Containing Chemotherapy, Does it Effect Intraperitoneal Hyperthermic Chemotherapy Perfusion?

INTRODUCTION

Patients undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are commonly exposed to oxaliplatin neoadjuvant chemotherapy (NAT) regimens. The impact of systemic exposure to oxaliplatin prior to HIPEC with oxaliplatin is unknown.

METHODS

We conducted a retrospective review of our institutional registry of CRS/HIPEC cases who received oxaliplatin-containing NAT, and compared patients who underwent HIPEC with oxaliplatin versus cases perfused with mitomycin C. The primary outcome was survival, defined by overall survival (OS) and disease-free survival (DFS). Subgroup analysis was performed based on primary tumor etiology and completeness of cytoreduction.

RESULTS

A total of 333 cases satisfied the selection criteria-159 appendiceal primaries (all high-grade disease) and 174 colorectal cases. Thirty-one cases (9.3%) underwent HIPEC with oxaliplatin, with the remaining 302 cases (90.7%) receiving mitomycin C. Both cohorts were identical in regard to baseline characteristics, and both groups were alike in regard to NAT regimens and oxaliplatin exposure. There was no difference in survival outcomes. OS times were 2.9 (± 2.8) and 2.8 ( ± 3.6) years for oxaliplatin and mitomycin C perfusions, respectively (p = 0.94), and the 5-year OS rates were also similar at 9.7 and 18.5% (odds ratio [OR] 0.49, 95% confidence interval [CI] 0.14-1.67, p = 0.24) for oxaliplatin and mitomycin cases, respectively. Likewise, DFS findings were similar, with survival of 2.5 (± 4.5) and 1.8 (± 2.4) years for oxaliplatin and mitomycin perfusions, respectively (p = 0.21). There was no difference in 5-year DFS rates, at 10.5 and 7.8% (OR 1.39, 95% CI 0.30-6.56, p = 0.68) for oxaliplatin and mitomycin C, respectively. Subgroup analysis found minimal discordant findings from the main results.

CONCLUSION

This analysis found no discernable association with NAT oxaliplatin exposure in regard to survival outcomes following CRS/HIPEC stratified out by perfusion agent.

Plasma Exosome Gene Signature Differentiates Colon Cancer from Healthy Controls

BACKGROUND

Liquid biopsies have become an integral part of cancer management as minimally invasive options to detect molecular and genetic changes. However, current options show poor sensitivity in peritoneal carcinomatosis (PC). Novel exosome-based liquid biopsies may provide critical information on these challenging tumors. In this initial feasibility analysis, we identified an exosome gene signature of 445 genes (ExoSig445) from colon cancer patients, including those with PC, that is distinct from healthy controls.

METHODS

Plasma exosomes from 42 patients with metastatic and non-metastatic colon cancer and 10 healthy controls were isolated and verified. RNAseq analysis of exosomal RNA was performed and differentially expressed genes (DEGs) were identified by the DESeq2 algorithm. The ability of RNA transcripts to discriminate control and cancer cases was assessed by principal component analysis (PCA) and Bayesian compound covariate predictor classification. An exosomal gene signature was compared with tumor expression profiles of The Cancer Genome Atlas.

RESULTS

Unsupervised PCA using exosomal genes with greatest expression variance showed stark separation between controls and patient samples. Using separate training and test sets, gene classifiers were constructed capable of discriminating control and patient samples with 100% accuracy. Using a stringent statistical threshold, 445 DEGs fully delineated control from cancer samples. Furthermore, 58 of these exosomal DEGs were found to be overexpressed in colon tumors.

CONCLUSIONS

Plasma exosomal RNAs can robustly discriminate colon cancer patients, including patients with PC, from healthy controls. ExoSig445 can potentially be developed as a highly sensitive liquid biopsy test in colon cancer.

Impact of myometrium invasion on survival outcomes following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC)

INTRODUCTION

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is an effective surgical intervention for peritoneal surface malignancy. The effect of myometrium invasion on outcomes is unknown.

METHODS

Retrospective review of our institutional registry with analysis of CRS-HIPEC cases involving a hysterectomy. Compared cases with myometrium invasion versus those without invasion. Primary outcome was survival as measured by overall survival (OS) and disease-free survival (DFS). Secondary outcome was the evaluation of risk factors for myometrium invasion based on multivariate analysis.

RESULTS

A total of 126 cases of CRS-HIPEC involving a hysterectomy were identified. Ninety-seven cases (76.9%) had no myometrium invasion and the remaining 29 cases (23.1%) had malignant invasion. The presence of myometrial invasion was a significant negative survival prognostic factor. The OS was halved with mean survival times of 2.8 (±2.3) versus 5.8 (±4.7) years for cases with and without invasion, respectively (p = 0.002). Five-year OS rates were also inferior with myometrium invasion at 17.4% versus 53.8% (odds ratio [OR] = 0.181, 95% confidence interval [CI]: 0.057-0.580, p = 0.002). A similar trend was present with DFS with mean survival times of 1.4 (±0.9) versus 3.7 (±3.9) years for noninvasion and invasion cases (p = 0.009). The 5-year DFS rates were 0% versus 34.8% (OR = 0.652, 95% CI: 0.549-0.775, p = 0.004). Secondary analysis significantly associated several risk factors with myometrium invasion to include lymph node positivity (OR = 2.539, 95% CI: 1.074-6.003, p = 0.012), colorectal primary tumors (OR = 2.248, 95% CI: 1.094-5.161, p = 0.035), and high-grade tumors (OR = 2.160, 95% CI: 1.080-4.820, p = 0.038).

CONCLUSION

Myometrium invasion is a significant negative prognostic factor for survival following CRS-HIPEC. Several risk factors are potentially predictive of identifying those at high-risk for myometrium invasion.

Survival Outcomes of Optimally Treated Colorectal Metastases: The Importance of R0 Status in Surgical Treatment of Hepatic and Peritoneal Surface Disease

BACKGROUND

Although colorectal hepatic metastases (HM) and peritoneal surface disease (PSD) are distinct biologic diseases, they may have similar long-term survival when optimally treated with surgery.

METHODS

This study retrospectively reviewed prospectively managed databases. Patients undergoing R0 or R1 resections were analyzed with descriptive statistics, the Kaplan-Meier method, and Cox regression. Survival was compared over time for the following periods: 1993-2006, 2007-2012, and 2013-2020.

RESULTS

The study enrolled 783 HM patients undergoing liver resection and 204 PSD patients undergoing cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC). Compared with PSD patients, HM patients more often had R0 resections (90.3% vs. 32.4%), less often had pre-procedure chemotherapy (52.4% vs. 92.1%), and less often were functionally independent (79.7% vs. 95.6%). The 5-year overall survival for HM was 40.9%, with a median survival period of 45.8 months versus 25.8% and 33.4 months, respectively, for PSD (p < 0.05). When stratified by resection status, R0 HM and R0 PSD did not differ significantly in median survival (49.0 vs. 45.4 months; p = 0.83). The median survival after R1 resection also was similar between HM and PSD (32.6 vs. 26.9 months; p = 0.59). Survival between the two groups again was similar over time when stratified by resection status. The predictors of survival for HM patients were R0 resection, number of lesions, intraoperative transfusion, age, and adjuvant chemotherapy. For the PSD patients, the predictors were peritoneal cancer index (PCI) score, estimated blood loss (EBL), and female gender.

CONCLUSION

The study showed that R0 resections are associated with improved outcomes and that median survival is similar between HM and PSD patients when it is achieved. Surveillance and treatment strategies that facilitate R0 resections are needed to improve results, particularly for PSD.

Long-Term Survival in Patients Treated with Cytoreduction and Heated Intraperitoneal Chemotherapy for Peritoneal Mesothelioma at a Single High-Volume Center

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare diagnosis with a dismal prognosis if untreated. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is shown to significantly improve survival. Our institution is uniquely positioned to report long-term outcomes in MPM with CRS-HIPEC, due to our robust peritoneal surface disease program existing over the past three decades.

METHODS

Our prospectively maintained, single-institution database of CRS-HIPEC cases was reviewed, identifying 111 consecutive patients with MPM over 28 years (1993-2021). Prognostic, operative, and pathologic factors were reviewed. Overall survival (OS) and conditional survival (CS) analyses were performed.

RESULTS

The average age was 55.1 years; 58.6% of patients were male; 17 of 111 patients (15.3%) had a second CRS-HIPEC. At first CRS-HIPEC, the average PCI score was 18.7, and the perfusate drugs were platinum-based (72.1%) and mitomycin C (27.9%). The resection status at first CRS-HIPEC was R2a (46.4%), followed by R0-1 (29.1%), and R2b-c (24.5%). Median OS was 3.3 years for the entire cohort, with 75th and 25th percentiles at 10.7 months and 10.6 years. Median CS was improved if patients survived to the 1-year postoperative mark (4.9 years, p < 0.01) and trended toward further improvement with each passing year. If 3-year postoperative survival was achieved, the median CS improved to 6.1 years.

CONCLUSIONS

This represents one of the largest and lengthiest, single-center, longitudinal, case series of peritoneal mesothelioma treated with CRS-HIPEC. The OS suggests efficacy for CRS-HIPEC for MPM. Long-term survival improves significantly after patients achieve the 1-year, postoperative mark.

Switching Perfusion Agents for Repeat Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy: Surgical Dogma or Evidence-Based Practice?

BACKGROUND

A common practice is to switch chemotherapy perfusion agents for repeat cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). However, there is a paucity of objective benefit with this practice.

METHODS

A retrospective review of our institutional registry involving repeat CRS-HIPEC cases was conducted, comparing cases that underwent a perfusion agent switch versus those cases with no switch. The primary outcome of this study was survival, measured by overall survival (OS) and disease-free survival (DFS). A subgroup analysis was performed on the basis of primary etiology.

RESULTS

A total of 101 cases met selection criteria. Mitomycin C was used as the index perfusion agent in 84% of cases, while oxaliplatin was utilized in the remaining 16% of cases. In total, 66 cases underwent a perfusion switch, with 35 cases using the same agent. Analysis revealed no survival benefit with HIPEC perfusion switch. For OS, there were similar mean survival times of 5.2 (± 4.1) years and 5.1 (± 3.6) years for cases with perfusion switch and no perfusion switch, respectively (P = 0.985). The 5-year OS rates were also similar at 61.4% and 53.3% for switch and non-switch cases, respectively [odds ratio (OR) 0.41, 95% confidence interval (CI) 0.54-3.56, P = 0.49]. Mean DFS was 4.0 (± 4.2) years and 3.6 (± 3.8) years for switch and non-switch cases, respectively (P = 0.74). The 5-year DFS rates had a greater difference with statistical trend, with rates of 53% versus 28% for switch and non-switch cases, respectively (OR 2.91, 95% CI 0.86-9.86, P = 0.081). Subgroup analysis had a similar trend to the main results.

CONCLUSIONS

The study findings revealed no survival benefit with switching perfusion agents. Analysis suggests that the practice of perfusion switch is ineffective.

Management of peritoneal surface metastases from colorectal cancer: Cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, pressurized intraperitoneal chemotherapy, and beyond

This article provides a contemporary review of the current surgical management of peritoneal surface malignancy (PSM) of colorectal origin. A brief review of the founding history of surgical intervention for PSM is followed by a focused review of the level I evidence, current clinical questions, and evolving advancements. While not intended to address all the facets of PSM, this review aims to provide the reader with the essential knowledge and resources to effectively provide surgical care for carcinomatosis due to colorectal malignancies.

HIPEC after neoadjuvant chemotherapy is associated with acceptable toxicity and favorable quality of life in newly diagnosed advanced ovarian cancer patients

OBJECTIVE

To evaluate toxicity, quality of life and PFS in patients with advanced ovarian cancer who underwent neoadjuvant chemotherapy (NAC) followed by CRS and HIPEC with carboplatin.

METHODS

Patients with stage IIIC or IVA epithelial ovarian cancer, who were not candidates for primary CRS, were enrolled in this phase two trial. Patients received 3-6 cycles of NAC with an IV carboplatin doublet followed by CRS with HIPEC (carboplatin 800 mg/m2 for 90 min). They were followed for at least 12 months to assess for adverse events, quality of life (QOL) and disease progression. QOL was measured using the Functional Assessment of Cancer Therapy-Ovarian (FACT-O) questionnaires prior to CRS and post-operatively at 6 weeks, 3 months, and 6 months after CRS.

RESULTS

Twenty patients were enrolled. HIPEC was completed successfully in all twenty patients, and there was no peri-operative mortality. Twelve (70.6%) patients experienced a grade 3 or 4 toxicity; most commonly anemia (59%), thrombocytopenia (29%), and hypokalemia (24%). There was no significant change between the pre-operative and postoperative 6 weeks, 3 month, and 6 month FACT-O, NTX, and AD scores. Nine (45%) patients have experienced disease recurrence to date. The median progression free survival in this cohort is 11.2 months (2.5-23.7 months).

CONCLUSION

The addition of HIPEC with carboplatin to interval CRS was well tolerated in patient population. Myelosuppression was the most common adverse event. CRS with HIPEC did not adversely impact these patients' QOL indices. The efficacy of this regimen should be further evaluated in a larger clinical trial.

Therapeutic Value of Sentinel Lymph Node Biopsy in Patients With Melanoma: A Randomized Clinical Trial

Importance

Sentinel lymph node (SLN) biopsy is a standard staging procedure for cutaneous melanoma. Regional disease control is a clinically important therapeutic goal of surgical intervention, including nodal surgery.

Objective

To determine how frequently SLN biopsy without completion lymph node dissection (CLND) results in long-term regional nodal disease control in patients with SLN metastases.

Design, Setting, and Participants

The second Multicenter Selective Lymphadenectomy Trial (MSLT-II), a prospective multicenter randomized clinical trial, randomized participants with SLN metastases to either CLND or nodal observation. The current analysis examines observation patients with regard to regional nodal recurrence. Trial patients were aged 18 to 75 years with melanoma metastatic to SLN(s). Data were collected from December 2004 to April 2019, and data were analyzed from July 2020 to January 2022.

Interventions

Nodal observation with ultrasonography rather than CLND.

Main Outcomes and Measures

In-basin nodal recurrence.

Results

Of 823 included patients, 479 (58.2%) were male, and the mean (SD) age was 52.8 (13.8) years. Among 855 observed basins, at 10 years, 80.2% (actuarial; 95% CI, 77-83) of basins were free of nodal recurrence. By univariable analysis, freedom from regional nodal recurrence was associated with age younger than 50 years (hazard ratio [HR], 0.49; 95% CI, 0.34-0.70; P < .001), nonulcerated melanoma (HR, 0.36; 95% CI, 0.36-0.49; P < .001), thinner primary melanoma (less than 1.5 mm; HR, 0.46; 95% CI, 0.27-0.78; P = .004), axillary basin (HR, 0.61; 95% CI, 0.44-0.86; P = .005), fewer positive SLNs (1 vs 3 or more; HR, 0.32; 95% CI, 0.14-0.75; P = .008), and SLN tumor burden (measured by diameter less than 1 mm [HR, 0.39; 95% CI, 0.26-0.60; P = .001] or less than 5% area [HR, 0.36; 95% CI, 0.24-0.54; P < .001]). By multivariable analysis, younger age (HR, 0.57; 95% CI, 0.39-0.84; P = .004), thinner primary melanoma (HR, 0.40; 95% CI, 0.22-0.70; P = .002), axillary basin (HR, 0.55; 95% CI, 0.31-0.96; P = .03), SLN metastasis diameter less than 1 mm (HR, 0.52; 95% CI, 0.33-0.81; P = .007), and area less than 5% (HR, 0.58; 95% CI, 0.38-0.88; P = .01) were associated with basin control. When looking at the identified risk factors of age (50 years or older), ulceration, Breslow thickness greater than 3.5 mm, nonaxillary basin, and tumor burden of maximum diameter of 1 mm or greater and/or metastasis area of 5% or greater and excluding missing value cases, basin disease-free rates at 5 years were 96% (95% CI, 88-100) for patients with 0 risk factors, 89% (95% CI, 82-96) for 1 risk factor, 86% (95% CI, 80-93) for 2 risk factors, 80% (95% CI, 71-89) for 3 risk factors, 61% (95% CI, 48-74) for 4 risk factors, and 54% (95% CI, 36-72) for 5 or 6 risk factors.

Conclusions and Relevance

This randomized clinical trial was the largest prospective evaluation of long-term regional basin control in patients with melanoma who had nodal observation after removal of a positive SLN. SLN biopsy without CLND cleared disease in the affected nodal basin in most patients, even those with multiple risk factors for in-basin recurrence. In addition to its well-validated value in staging, SLN biopsy may also be regarded as therapeutic in some patients.

Trial Registration

ClinicalTrials.gov Identifier: NCT00297895.

Omission of Radiation in Conservative Treatment for Breast Cancer: Opportunity for De-escalation of Care

INTRODUCTION

De-escalation of breast cancer treatment aims to reduce patient and financial toxicity without compromising outcomes. Level I evidence and National Comprehensive Cancer Network guidelines support omission of adjuvant radiation in patients aged >70 y with hormone-sensitive, pT1N0M0 invasive breast cancer treated with endocrine therapy. We evaluated radiation use in patients eligible for guideline concordant omission of radiation.

METHODS

Subgroup analysis of patients eligible for radiation omission from two pooled randomized controlled trials, which included stage 0-III breast cancer patients undergoing breast conserving surgery, was performed to evaluate factors associated with radiation use.

RESULTS

Of 631 patients, 47 (7.4%) met radiation omission criteria and were treated by 14 surgeons at eight institutions. The mean age was 75.3 (standard deviation + 4.4) y. Majority of patients identified as White (n = 46; 97.9%) and non-Hispanic (n = 44; 93.6%). The mean tumor size was 1.0 cm; 37 patients (88.1%) had ductal, 4 patients (9.5%) had lobular, and 17 patients (40.5%) had low-grade disease. Among patients eligible for radiation omission, 34 (72.3%) patients received adjuvant radiation. Those who received radiation were significantly younger than those who did not (74 y, interquartile range = 4 y, versus 78 y, interquartile range = 11 y, P = 0.03). There was no difference in radiation use based on size (P = 0.4), histology (P = 0.5), grade (P = 0.7), race (P = 1), ethnicity (P = 0.6), institution (P = 0.1), gender of the surgeon (P = 0.7), or surgeon (P = 0.1).

CONCLUSIONS

Fewer than 10% of patients undergoing breast conservation met criteria for radiation omission. Nearly three-quarters received radiation therapy with younger age being a driver of radiation use, suggesting ample opportunity for de-escalation, particularly among younger eligible patients.

Patient-Specific Sarcoma Organoids for Personalized Translational Research: Unification of the Operating Room with Rare Cancer Research and Clinical Implications

INTRODUCTION

Sarcoma clinical outcomes have been stagnant for decades due to heterogeneity of primaries, lack of comprehensive preclinical models, and rarity of disease. We hypothesized that engineering hydrogel-based sarcoma organoids directly from the patient without xenogeneic extracellular matrices (ECMs) or growth factors is routinely feasible and allows rare tumors to remain viable as avatars for personalized research.

METHODS

Surgically resected sarcomas (angiosarcomas, leiomyosarcoma, gastrointestinal stromal tumor, liposarcoma, myxofibrosarcoma, dermatofibrosarcoma protuberans [DFSP], and pleiomorphic abdominal sarcoma) were dissociated and incorporated into a hyaluronic acid and collagen-based ECM hydrogel and screened for chemotherapy efficacy. A subset of organoids was enriched with a patient-matched immune system for screening of immunotherapy efficacy (iPTOs). Response to treatment was assessed using LIVE/DEAD staining and metabolic assays.

RESULTS

Sixteen sarcomas were biofabricated into three-dimensional (3D) patient-specific sarcoma organoids with a 100% success rate. Average time from organoid development to initiation of drug testing was 7 days. Enrichment of organoids with immune system components derived from either peripheral blood mononuclear cells or lymph node cells was performed in 10/16 (62.5%) patients; 4/12 (33%) organoids did not respond to chemotherapy, while response to immunotherapy was observed in 2/10 (20%) iPTOs.

CONCLUSIONS

A large subset of sarcoma organoids does not exhibit response to chemotherapy or immunotherapy, as currently seen in clinical practice. Routine development of sarcoma hydrogel-based organoids directly from the operating room is a feasible platform, allowing for such rare tumors to remain viable for personalized translational research.

Abstract 3076: Low PTIP expression is linked to HIPEC resistance in appendiceal cancer

Introduction: Peritoneal carcinomatosis is a late-stage complication of appendiceal cancer, leading to decreased life expectancy and poor quality of life. Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has improved overall survival. Despite this advancement, there remain challenges in determining which patients may benefit from the procedure. Hyperthermia has been shown to potentiate chemotherapy toxicity through interfering with DNA repair, suggesting DNA repair proteins could serve as a predictive marker of clinical outcomes. Herein we applied patient derived tumor organoids (PTOs) to examine the personalized impact of DNA repair mechanisms in efficacy of HIPEC.

Methods: Tumor specimens were obtained from patients undergoing CRS under IRB protocols. Specimens were dissociated and incorporated into a collagen-hyaluronic acid organoid model and treated with clinical HIPEC regimens using mitomycin C (MMC) and oxaliplatin under normothermic (37°C) and heated conditions (42°C) for two hours. The post-treatment viability average responses were aggregated and used for statistical analysis. Treated organoids and tissues were processed histologically and qPCR was performed on patient tumor cells to determine expression of DNA damage markers and DNA damage response.

Results: From June 2019-October 2021, 59 appendiceal tumor tissues from 35 patients with peritoneal carcinomatosis were acquired. 53 PTO groups, from 17 high grade and 36 low grade tumors, were successfully fabricated and tested for HIPEC sensitivity. Hyperthermia potentiated the cytotoxic effect for both MMC (35% vs 57%, p&lt;0.0001, 3/17 HGA and 6/36 LGA PTO sets) and oxaliplatin (41% vs 66%, p&lt;0.0001, 5/17 HGA and 13/37 LGA PTOs). Within the thermosensitive cohort, MMC and oxaliplatin based HIPEC, resulted in similar post perfusion viabilities (35% vs 41%, p=0.25). Furthermore, low and high grade primaries exhibited similar post perfusion viabilities for both MMC (32% vs 40%, p=0.25) and oxaliplatin (36% vs 49%, p=0.08)To test if resistance to HIPEC was associated with increased expression of DNA damage repair proteins in treated organoids, we examined Pax2-Interacting-Protein (PTIP), an important DNA repair protein for both chromatin remodeling and interactions with other DNA repair proteins. Lower PTIP expression in appendiceal tissue sections is correlated with HIPEC treatment sensitivity for both oxaliplatin when compared to high expression (32% vs 49%, p=0.02) and MMC (29% vs 38%, p=0.05). qPCR results confirmed these observations in PTOs, stratifying them into responding and non-responding groups.

Conclusions: Decreased expression of PTIP offers resistance in appendiceal cancer patients treated with HIPEC. PTOs can serve to determine personalized efficacy of HIPEC regimens both at the level of selection of perfusion chemotherapy agent or application of hyperthermia.

Citation Format: Steven D. Forsythe, Richard A. Erali, Preston Laney, Allan M. Johansen, Shyama Sasikumar, Perry Shen, Edward A. Levine, Shay Soker, Konstantinos I. Votanopoulos. Low PTIP expression is linked to HIPEC resistance in appendiceal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3076.

Repeat Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Cancers with Peritoneal Metastasis: A 30-year Institutional Experience

BACKGROUND

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) improves survival in abdominal cancer patients with metastatic disease limited to the peritoneal cavity. Patients are increasingly being offered repeat CRS-HIPECs for peritoneal recurrence. However, in this rare clinical scenario, the survival benefit of performing repeat CRS-HIPEC operations remains unclear.

METHODS

A retrospective review of the CRS-HIPEC database at Wake Forest Baptist Medical Center was performed over a 30-year timespan. From 1547 patients with appendix cancers, colorectal cancers, mesotheliomas, and other miscellaneous cancers, 156 received more than one CRS-HIPEC. Kaplan-Meier survival analysis was performed using overall survival (OS) from the time of surgery as the primary endpoint. Multi-variable Cox proportional hazards regression modelling was performed on pertinent clinical variables.

RESULTS

Patients who received multiple CRS-HIPECs had significantly better median OS (10.7 years) versus those who received one CRS-HIPEC (2.5 years), with appendix cancers faring best (12.9 years). Resection status R2a or better was achieved in 76.4% of repeat CRS-HIPECs. There were no significant changes in complication rates after repeat CRS-HIPEC. On multivariate analysis of repeat CRS-HIPEC, patients with appendix and colorectal cancers, heart disease, and poor functional status were independently associated with poor OS. Factors not independently associated with OS were age, sex, body mass index, race, diabetes, lung disease, smoking history, and systemic chemotherapy between CRS-HIPECs.

CONCLUSIONS

Performing multiple CRS-HIPEC operations on appropriate surgical candidates may significantly prolong survival. Appendix cancers derived the greatest benefit. Satisfactory resection margins and complication rates are comparable to first cases and achievable in repeat CRS-HIPEC procedures.

An International Registry of Peritoneal Carcinomatosis from Appendiceal Goblet Cell Carcinoma Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

PURPOSE

Peritoneal carcinomatosis from appendiceal goblet cell carcinoma (A-GCC) is a rare and aggressive form of appendiceal tumor. Cytoreductive surgery (CRS) and hyperthermic intra peritoneal chemotherapy (HIPEC) was reported as an interesting alternative regarding survival compared to surgery without HIPEC and/or systemic chemotherapy. Our aim was to evaluate the impact of CRS and HIPEC for patients presenting A-GCC through an international registry.

METHODS

A prospective multicenter international database was retrospectively searched to identify all patients with A-GCC tumor and peritoneal metastases who underwent CRS and HIPEC through the Peritoneal Surface Oncology Group International (PSOGI). The post-operative complications, long-term results, and principal prognostic factors were analyzed.

RESULTS

The analysis included 83 patients. After a median follow-up of 47 months, the median overall survival (OS) was 34.6 months. The 3- and 5-year OS was 48.5% and 35.7%, respectively. Patients who underwent complete macroscopic CRS had a significantly better survival than those treated with incomplete CRS. The 5-year OS was 44% and 0% for patients who underwent complete, and incomplete CRS, respectively (HR 9.65, p < 0.001). Lymph node involvement and preoperative chemotherapy were also predictive of a worse prognosis. There were 3 postoperative deaths, and 30% of the patients had major complications.

CONCLUSION

CRS and HIPEC may increase long-term survival in selected patients with peritoneal metastases of A-GCC origin, especially when complete CRS is achieved. Ideally, randomized control trials or more retrospective data are needed to confirm CRS and HIPEC as the gold standard in this pathology.

Timing of Repeat Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy for Recurrent Low-Grade Appendiceal Mucinous Neoplasms

BACKGROUND

Low-grade appendiceal mucinous neoplasm (LAMN) with peritoneal involvement is a common indication for cytoreductive surgery with heated intraperitoneal chemotherapy (CRS/HIPEC). With peritoneal recurrence, patients are increasingly being offered repeat CRS/HIPECs, however optimal timing for a second CRS/HIPEC remains unknown.

METHODS

A prospectively maintained 30-year database at our high-volume HIPEC center was analyzed retrospectively for patients with LAMNs and peritoneal recurrence receiving one or two CRS/HIPECs. Kaplan-Meier survival analysis, linear regression modeling, and Cox proportional hazards regression analyses were performed.

RESULTS

Overall, 143 patients with LAMNs who underwent CRS/HIPECs had confirmed postoperative peritoneal recurrence. Of these patients, 85 underwent one CRS/HIPEC and 58 underwent two CRS/HIPECs. The groups had significant differences in age, with younger patients more likely to undergo a second CRS/HIPEC (48.5 vs. 58.0 years; p < 0.001). The median overall survival (OS) for the group undergoing two CRS/HIPECs was approximately four times longer compared with the group undergoing one CRS/HIPEC (227.1 vs. 54.5 months; p < 0.0001). The time from recurrence to the second CRS/HIPEC was not significantly associated with OS from the time of the first operation. Instead, a shorter time between the first CRS/HIPEC and recurrence was significantly associated with shorter OS from the time of the first operation (p = 0.037).

CONCLUSION

In peritoneal LAMNs with recurrence, receiving two CRS/HIPECs was associated with better OS compared with receiving one CRS/HIPEC. Longer time to recurrence was a good prognostic factor. Delay between recurrence and second CRS/HIPEC had no apparent impact on OS from the first CRS/HIPEC; thus, immediate or delayed reoperative intervention are both reasonable approaches.

Optimal Adjuvant Treatment Approach After Upfront Resection of Pancreatic Cancer: Revisiting the Role of Radiation Based on Pathologic Features

OBJECTIVE

To identify the survival benefit of different adjuvant approaches and factors influencing their efficacy after upfront resection of pancreatic ductal adenocarcinoma (PDAC).

SUMMARY BACKGROUND DATA

The optimal adjuvant approach for PDAC remains controversial.

METHODS

Patients from the National Cancer Database who underwent upfront PDAC resection from 2010 to 2014 were analyzed to determine clinical outcomes of different adjuvant treatment approaches, stratified according to pathologic characteristics. Factors associated with overall survival were identified with multivariable logistic regression and Cox proportional hazards were used to compare overall survival of different treatment approaches in the whole cohort, and propensity score matched groups.

RESULTS

We included 16,709 patients who underwent upfront resection of PDAC. On multivariable analysis, tumor size, grade, positive margin, nodal involvement, lymphovascular invasion (LVI), stage, lymph node ratio, not receiving chemotherapy, and/or radiation were predictors for worse survival. In the presence of at least 1 high-risk pathologic feature (nodal or margin involvement or LVI) chemotherapy with subsequent radiation provided the most significant survival benefit (median survivals: 24.8 vs 21.0 mo for adjuvant chemotherapy; HR = 0.81; 95% CI: 0.77-0.86; P < 0.001 in propensity score matching). The addition of radiation to adjuvant chemotherapy did not significantly improve overall survival in those with no high-risk pathologic features (median survivals: 54.6 vs 42.7 mo for adjuvant chemotherapy; HR=0.90; 95% CI: 0.75-1.08; P = 0.25 in propensity score matching).

CONCLUSIONS

In the presence of any high-risk pathologic features (nodal or margin involvement or LVI), adjuvant chemotherapy followed by radiation provides a better survival advantage over chemotherapy alone after upfront resection of PDAC.

Utility of hyperthermic intraperitoneal chemotherapy in cases of incomplete cytoreductive surgery

INTRODUCTION

Hyperthermic intraperitoneal chemotherapy (HIPEC) during cytoreductive surgery (CRS) is typically reserved for a complete or optimal cytoreduction. There is the potential for therapeutic effect of HIPEC with an incomplete cytoreduction, particularly for near optimal cytoreductions.

METHODS

Retrospective review of incomplete cytoreductions (R2b, R2c) for appendiceal and colorectal primaries. Primary endpoints were overall survival (OS) and progression-free survival (PFS). Subgroup analysis for primary etiology and specific cytoreductive score.

RESULTS

A total of 121 cases of incomplete CRS, 74 CRS alone, and 47 CRS-HIPEC. For the entire study group there was a survival benefit with HIPEC. OS and PFS were 2.3 versus 1.4 (p = 0.001) and 1.6 versus 0.7 (p < 0.0001) respectively for cases with and without HIPEC. Subgroup analysis of appendiceal neoplasms, 43 CRS-HIPEC and 50 CRS alone, found HIPEC benefit persisted; OS and PFS were 2.4 versus 1.5 (p = 0.016) and 1.7 versus 0.8 (p < 0.0001), respectively for cases with and without HIPEC. Benefit most pronounced in low-grade cases with doubling of the OS and PFS (p = 0.004). With colorectal primary cases, 10 CRS-HIPEC and 18 CRS alone, no difference in OS and PFS. When stratifying out by cytoreduction scores, R2b and R2c, HIPEC only provided a benefit for R2b cases; OS and PFS for R2b cases were 2.28 versus 1.01 (p = 0.011) and 1.67 versus 0.75 (p = 0.001), respectively for cases with and without HIPEC.

CONCLUSION

HIPEC has utility for incomplete cytoreductions with appendiceal neoplasms, greatest effect with low-grade appendiceal neoplasms. HIPEC is only beneficial for near optimal cytoreductions (R2b).

Factors Affecting Time to Surgery in Breast Cancer Patients

BACKGROUND

We sought to determine factors affecting time to surgery (TTS) to identify potential modifiable factors to improve timeliness of care.

METHODS

Patients with clinical stage 0-3 breast cancer undergoing partial mastectomy in 2 clinical trials, conducted in ten centers across the US, were analyzed. No preoperative workup was mandated by the study; those receiving neoadjuvant therapy were excluded.

RESULTS

The median TTS among the 583 patients in this cohort was 34 days (range: 1-289). Patient age, race, tumor palpability, and genomic subtype did not influence timeliness of care defined as TTS ≤30 days. Hispanic patients less likely to have a TTS ≤30 days (P = .001). There was significant variation in TTS by surgeon (P < .001); those practicing in an academic center more likely to have TTS ≤30 days than those in a community setting (55.1% vs 19.3%, P < .001). Patients who had a preoperative ultrasound had a similar TTS to those who did not (TTS ≤30 days 41.9% vs 51.9%, respectively, P = .109), but those who had a preoperative MRI had a significantly increased TTS (TTS ≤30 days 25.0% vs 50.9%, P < .001). On multivariate analysis, patient ethnicity was no longer significantly associated with TTS ≤30 (P = .150). Rather, use of MRI (OR: .438; 95% CI: .287-.668, P < .001) and community practice type (OR: .324; 95% CI: .194-.541, P < .001) remained independent predictors of lower likelihood of TTS ≤30 days.

CONCLUSIONS

Preoperative MRI significantly increases time to surgery; surgeons should consider this in deciding on its use.

Evaluation of the Axillary Surgery Performed in Clinically Node-Positive Breast Cancer Patients Following Neoadjuvant Chemotherapy

BACKGROUND

The American College of Surgeons Oncology Group Z1071 trial in 2013 demonstrated the fesability of sentinel lymph node biopsy in clinically node-positive patients following neoadjuvant chemotherapy. The goal of this study was to determine the continued impact of this study on our practice pattern.

MATERIALS AND METHODS

This is a retrospective review of institutional changes in the management of axillary nodal disease following the publication of Z1071. Patients with clinically node-positive disease that completed neoadjuvant chemotherapy between 2014 and 2020 were included. The Cocoran-Armitage trend test was used to analyze change in categorical variables over time, and the Spearman's rank coefficient was used to analyze two-ranked variables.

RESULTS

A cohort of 102 patients were included in the study and demonstrated that the number of sentinel lymph node biopsies to evaluate axillary disease increased over time. Additionally, the number of biopsies of suspicious nodes, and the use of marker clips on the biopsied nodes increased over time.

CONCLUSION

Our institution has continued to incorporate the result from Z1071 in our practice patterns.