Neoadjuvant Immunotherapy Leads to Major Response and Low Recurrence in Localized Mismatch Repair-Deficient Colorectal Cancer

Systematic Review of Neoadjuvant Immunotherapy for Mismatch Repair Deficient Locally Advanced Colon Cancer: An Emerging Strategy

BACKGROUND

In April 2023, the National Comprehensive Cancer Network endorsed neoadjuvant immunotherapy for select patients with nonmetastatic mismatch repair deficient colon cancer. Approximately 15% of incident colon cancers are mismatch repair deficient, resulting in a distinct molecular subtype with high microsatellite instability that is responsive to immune checkpoint inhibition.

OBJECTIVE

To describe the existing evidence supporting neoadjuvant immunotherapy for mismatch repair deficient, microsatellite unstable nonmetastatic colon cancer.

DATA SOURCES

A medical librarian performed PubMed, Embase, and Web of Science searches most recently on April 24, 2023. The PubMed search was re-run on September 26, 2023, to identify any additional studies published between April 24 and September 26, 2023.

STUDY SELECTION

Two authors screened titles and abstracts in the published studies. The inclusion criteria were 1) English language, 2) adults with primary cancer of the colon, 3) nonmetastatic disease, 4) neoadjuvant immunotherapy, and 5) reporting on 10 or more cases.

INTERVENTION

Neoadjuvant immunotherapy.

MAIN OUTCOME MEASURES

Safety (grade 3+ treatment-related adverse events) and efficacy (complete pathologic responses).

RESULTS

From 7691 studies identified, 6370 were screened and 8 were included. Various agents, dosing regimens, and treatment durations were used, with durations of immunotherapy ranging from 1 to 16 cycles. Complete R0 resections were consistently achieved in 98% to 100% of resections. Of patients who received neoadjuvant immunotherapy and underwent resection, 50% to 91% had ypT0N0 pathology. The safety profiles were generally favorable, with grade 1 to 2 treatment-related adverse events (mostly immune-related) during immunotherapy reported in 22.2% to 70% of patients. Postoperative complications after neoadjuvant immunotherapy were reassuring, with no severe complications reported.

LIMITATIONS

Small number of heterogeneous and uncontrolled studies precluding a meta-analysis.

CONCLUSIONS

Neoadjuvant immune checkpoint inhibition is associated with high rates of pathologic complete responses in locally advanced colon cancer. The literature is limited, particularly for postoperative outcomes, and more studies are needed to understand the safety and positioning of these regimens in the neoadjuvant context.

Efficacy and Safety of Neoadjuvant Subcutaneous Envafolimab in dMMR/MSI-H Locally Advanced Colon Cancer

BACKGROUND

Neoadjuvant immunotherapy with programmed death-ligand 1 blockade for colon cancer, especially for mismatch repair-deficient (dMMR)/high microsatellite instability (MSI-H) colon cancer, has gained considerable attention recently.

OBJECTIVE

This study aimed to assess the safety and efficacy of neoadjuvant subcutaneous envafolimab in patients with dMMR/MSI-H locally advanced colon cancer.

METHODS

Patients with dMMR/MSI-H locally advanced colon cancer treated with envafolimab at Sun Yat-sen University Cancer Center and Yunnan Cancer Hospital from October 2021 to July 2023 were retrospectively reviewed and analyzed. The primary endpoint was the pathological complete response (CR) rate, and secondary endpoints were treatment-related adverse events and complete clinical response rate.

RESULTS

Overall, 15 patients were analyzed. After neoadjuvant immunotherapy with envafolimab, six patients achieved a CR, with five partial responses, and four stable disease. Three patients achieving a complete clinical response chose to accept a "watch and wait" strategy, and surgery was performed in 12 patients. Postoperative pathology results revealed seven patients achieved pathological CRs, and five patients achieved tumor regression grade 2, with 66.7% of the total CR rate. The most common treatment-related adverse events were pruritus and rash (40%), with no severe cases. No recurrences occurred over a 7.9-month follow-up.

CONCLUSIONS

Envafolimab yielded promising surgical outcomes and safety in dMMR/MSI-H locally advanced colon cancer, representing a promising treatment modality for this population.

Immunotherapy and radiotherapy for older patients with locally advanced rectal cancer unfit for surgery or decline surgery: a practical proposal by the International Geriatric Radiotherapy Group

The standard of care for locally advanced rectal cancer is total neoadjuvant therapy followed by surgical resection. Current evidence suggests that selected patients may be able to delay or avoid surgery without affecting survival rates if they achieve a complete clinical response (CCR). However, for older cancer patients who are too frail for surgery or decline the surgical procedure, local recurrence may lead to a deterioration of patient quality of life. Thus, for clinicians, a treatment algorithm which is well tolerated and may improve CCR in older and frail patients with rectal cancer may improve the potential for prolonged remission and potential cure. Recently, immunotherapy with check point inhibitors (CPI) is a promising treatment in selected patients with high expression of program death ligands receptor 1 (PD- L1). Radiotherapy may enhance PD-L1 expression in rectal cancer and may improve response rate to immunotherapy. We propose an algorithm combining immunotherapy and radiotherapy for older patients with locally advanced rectal cancer who are too frail for surgery or who decline surgery.

Current landscape of preoperative neoadjuvant therapies for initial resectable colorectal cancer liver metastasis

Colorectal cancer liver metastasis (CRLM) presents a clinical challenge, and optimizing treatment strategies is crucial for improving patient outcomes. Surgical resection, a key element in achieving prolonged survival, is often linked to a heightened risk of recurrence. Acknowledging the potential benefits of preoperative neoadjuvant chemotherapy in managing resectable liver metastases, this approach has gained attention for its role in tumor downsizing, assessing biological behavior, and reducing the risk of postoperative recurrence. However, the use of neoadjuvant chemotherapy in initially resectable CRLM sparks ongoing debates. The balance between tumor reduction and the risk of hepatic injury, coupled with concerns about delaying surgery, necessitates a nuanced approach. This article explores recent research insights and draws upon the practical experiences at our center to address critical issues regarding considerations for initially resectable cases. Examining the criteria for patient selection and the judicious choice of neoadjuvant regimens are pivotal areas of discussion. Striking the right balance between maximizing treatment efficacy and minimizing adverse effects is imperative. The dynamic landscape of precision medicine is also reflected in the evolving role of gene testing, such as RAS/BRAF and PIK3CA, in tailoring neoadjuvant regimens. Furthermore, the review emphasizes the need for a multidisciplinary approach to navigate the complexities of CRLM. Integrating technical expertise and biological insights is crucial in refining neoadjuvant strategies. The management of progression following neoadjuvant chemotherapy requires a tailored approach, acknowledging the diverse biological behaviors that may emerge. In conclusion, this review aims to provide a comprehensive perspective on the considerations, challenges, and advancements in the use of neoadjuvant chemotherapy for initially resectable CRLM. By combining evidence-based insights with practical experiences, we aspire to contribute to the ongoing discourse on refining treatment paradigms for improved outcomes in patients with CRLM.

Surgical outcomes of cytoreductive nephrectomy in patients receiving systemic immunotherapy for advanced renal cell carcinoma

PURPOSE

The use of systemic immune checkpoint blockade before surgery is increasing in patients with metastatic renal cell carcinoma, however, the safety and feasibility of performing consolidative cytoreductive nephrectomy after the administration of systemic therapy are not well described.

PATIENTS AND METHODS

A retrospective review of patients undergoing nephrectomy was performed using our prospectively maintained institutional database. Patients who received preoperative systemic immunotherapy were identified, and the risk of postoperative complications were compared to those who underwent surgery without upfront systemic treatment. Perioperative characteristics and surgical complications within 90 days following surgery were recorded.

RESULTS

Overall, we identified 220 patients who underwent cytoreductive nephrectomy from April 2015 to December 2022, of which 46 patients (21%) received systemic therapy before undergoing surgery. Unadjusted rates of surgical complications included 20% (n = 35) in patients who did not receive upfront systemic therapy and 20% (n = 9) in those who received upfront systemic immunotherapy. In our propensity score analysis, there was no statistically significant association between receipt of upfront immunotherapy and 90-day surgical complications [odds ratio (OR): 1.82, 95% confidence interval (CI): 0.59-5.14; P = 0.3]. This model, however, demonstrated an association between receipt of upfront immunotherapy and an increased odds of requiring a blood transfusion [OR: 4.53, 95% CI: 1.83-11.7; P = 0.001].

CONCLUSION

In our cohort, there was no significant difference in surgical complications among patients who received systemic therapy before surgery compared to those who did not receive upfront systemic therapy. Cytoreductive nephrectomy is safe and with low rates of complications following the use of systemic therapy.

A recurrence-predictive model based on eight genes and tumor mutational burden/microsatellite instability status in Stage II/III colorectal cancer

BACKGROUND

Although adjuvant chemotherapy (ACT) is widely used to treat patients with Stage II/III colorectal cancer (CRC), administering ACT to specific patients remains a challenge. The decision to ACT requires an accurate assessment of recurrence risk and absolute treatment benefit. However, the traditional TNM staging system does not accurately assess a patient's individual risk of recurrence.

METHODS

To identify recurrence risk-related genetic factors for Stage II/III CRC patients after radical surgery, we conducted an analysis of whole-exome sequencing of 47 patients with Stage II/III CRC who underwent radical surgery at five institutions. Patients were grouped into non-recurrence group (NR, n = 24, recurrence-free survival [RFS] > 5 years) and recurrence group (R, n = 23, RFS <2 years). The TCGA-COAD/READ cohort was employed as the validation dataset.

RESULTS

A recurrence-predictive model (G8plus score) based on eight gene (CUL9, PCDHA12, HECTD3, DCX, SMARCA2, FAM193A, AATK, and SORCS2) mutations and tumor mutation burden/microsatellite instability (TMB/MSI) status was constructed, with 97.87% accuracy in our data and 100% negative predictive value in the TCGA-COAD/READ cohort. For the TCGA-COAD/READ cohort, the G8plus-high group had better RFS (HR = 0.22, p = 0.024); the G8plus-high tumors had significantly more infiltrated immune cell types, higher tertiary lymphoid structure signature scores, and higher immunological signature scores. The G8plus score was also a predict biomarker for immunotherapeutic in advanced CRC in the PUCH cohort.

CONCLUSIONS

In conclusion, the G8plus score is a powerful biomarker for predicting the risk of recurrence in patients with stage II/III CRC. It can be used to stratify patients who benefit from ACT and immunotherapy.

Neoadjuvant Immune Checkpoint Inhibitor Therapy for Localized Deficient Mismatch Repair Colorectal Cancer: A Review

Importance

Colorectal cancers (CRCs) with deficient DNA mismatch repair (dMMR) account for 15% of all CRCs. Deficient MMR is a predictive biomarker associated with responsiveness to immune checkpoint inhibitors (ICIs) in solid tumors, including CRC. The remarkable effectiveness of ICIs in metastatic CRC has led to their evaluation in the neoadjuvant and adjuvant treatment of localized disease.

Observations

Multiple prospective phase 2 studies in limited numbers of patients with localized dMMR CRC demonstrate high complete clinical and pathological response rates (60%-100%) to neoadjuvant ICIs, with low rates of grade 3 or higher ICI-related toxic effects. Given the median follow-up of 12 to 25 months in these studies, longer-term monitoring is needed to determine the durability of response and to ensure that oncologic outcomes are not compromised in patients undergoing nonoperative management. Neoadjuvant ICI therapy is especially attractive for patients with rectal cancer given the significant morbidity that accompanies pelvic irradiation and total mesorectal excision. Ongoing and planned prospective phase 2 trials will provide further data on important issues, including optimal neoadjuvant treatment duration, ICI monotherapy vs combination, and the need for adjuvant ICI therapy.

Conclusions and Relevance

While this review found that early results of neoadjuvant immunotherapy for localized dMMR CRC show high rates of major and complete pathological response, longer-term follow-up data are needed to ensure that oncologic outcomes are not compromised and are ideally improved. Neoadjuvant ICI therapy in localized dMMR CRC represents a potential paradigm shift with implications for organ preservation.

Perioperative immune checkpoint inhibition for colorectal cancer: recent advances and future directions

For colorectal cancer (CRC), surgical resection remains essential for achieving good prognoses. Unfortunately, numerous patients with locally advanced CRC and metastatic CRC failed to meet surgical indications or achieve pathological complete response after surgery. Perioperative therapy has been proven to effectively lower tumor staging and reduce recurrence and metastasis. Immune checkpoint inhibitors (ICIs) have shown unprecedented prolongation of survival time and satisfactory safety in patients with high microsatellite instability/deficient mismatch repair (MSI-H/dMMR), while the therapeutic effect obtained by patients with mismatch repair-proficient or microsatellite stable (pMMR/MSS) was considered minimal. However, recent studies found that certain CRC patients with dMMR/MSI-H presented intrinsic or acquired immune resistance, and pMMR/MSS CRC patients can also achieve better efficacy. Therefore, more predictors are required for screening patients with potential clinical benefits. Since the discovery of synergistic effects between immunotherapy, chemotherapy, and radiotherapy, different immunotherapy-based therapies have been applied to the perioperative therapy of CRC in an increasing number of research. This review comprehensively summarized the past and current progress of different combinations of immunotherapy in perioperative clinical trials for CRC, focusing on the efficacy and safety, and points out the direction for future development.

Nonoperative Management of dMMR/MSI-H Colorectal Cancer following Neoadjuvant Immunotherapy: A Narrative Review

Immunotherapy with PD-1 blockade has achieved a great success in colorectal cancers (CRCs) with high microsatellite instability (MSI-H) and deficient mismatch repair (dMMR), and has become the first-line therapy in metastatic setting. Studies of neoadjuvant immunotherapy also report exciting results, showing high rates of clinical complete response (cCR) and pathological complete response. The high efficacy and long duration of response of immunotherapy has prompt attempts to adopt watch-and-wait strategy for patients achieving cCR following the treatment. Thankfully, the watch-and-wait approach has been proposed for nearly 20 years for patients undergoing chemoradiotherapy and has gained ground among patients as well as clinicians. In this narrative review, we combed through the available information on immunotherapy for CRC and on the watch-and-wait strategy in chemoradiotherapy, and looked forward to a future where neoadjuvant immunotherapy as a curative therapy would play a big part in the treatment of MSI-H/dMMR CRC.

Neoadjuvant cemiplimab and surgery for stage II-IV cutaneous squamous-cell carcinoma: follow-up and survival outcomes of a single-arm, multicentre, phase 2 study

BACKGROUND

We previously reported rates of pathological complete responses (51% [95% CI 39-62] per independent central review, the primary endpoint) and major pathological responses (13% per independent central review, a secondary endpoint) to neoadjuvant cemiplimab (an anti-PD-1 inhibitor) among 79 patients with locoregionally advanced, resectable cutaneous squamous cell carcinoma. Here, we present follow-up data, including event-free, disease-free, and overall survival.

METHODS

This single-arm, multicentre, phase 2 study included patients aged 18 years or older with resectable stage II-IV (M0) cutaneous squamous cell carcinoma and Eastern Cooperative Oncology Group performance status of 0 or 1. Patients received up to four planned doses of neoadjuvant cemiplimab 350 mg intravenously every 3 weeks followed by curative-intent surgery. After surgery, per investigator discretion, patients received either adjuvant cemiplimab for up to 48 weeks, radiotherapy, or observation alone. Secondary endpoints included in this follow-up analysis are event-free survival, disease-free survival, and overall survival, all summarised using the Kaplan-Meier method. Activity and safety endpoints were analysed for all enrolled patients who received at least one dose of neoadjuvant cemiplimab. In this report, safety data are reported for all patients who received at least one dose of adjuvant cemiplimab. This trial is registered with ClinicalTrials.gov, NCT04154943, has completed enrolment and follow-up is ongoing.

FINDINGS

Between March 20, 2020, and July 8, 2021, 79 patients were enrolled. Median age was 73 years (IQR 66-81), 67 (85%) patients were male, 12 (15%) were female, 69 (87%) were White, one was Asian (1%), one was other race (1%), and race was not reported for eight (10%). As of data cutoff (Dec 1, 2022), median follow-up was 18·7 months (IQR 15·6-22·1) for all 79 patients. Among 70 patients who had surgery, 65 (93%) had post-surgical management data: 32 (49%) of 65 were observed postoperatively, 16 (25%) received adjuvant cemiplimab, and 17 (26%) received adjuvant radiotherapy. 11 (14%) of 79 patients had event-free survival events, with an estimated 12-month event-free survival of 89% (95% CI 79-94) for all patients. None of 40 patients who had a pathological complete response and one (10%) of ten patients with major pathological response had recurrence. Six (9%) of 70 patients who completed surgery had a disease-free survival event, with an estimated 12-month disease-free survival of 92% (95% CI 82-97). Nine (11%) of 79 patients died, with an estimated 12-month overall survival for all patients of 92% (95% CI 83-96). Four (25%) of 16 patients who received adjuvant cemiplimab treatment had grade 3 adverse events, including one (6%) who had increased blood potassium, one (6%) who had traumatic limb amputation, and two who had serious adverse events (one [6%] cardiomyopathy and one [6%] hypophysitis). There were no grade 4 adverse events or treatment-related deaths.

INTERPRETATION

For patients with resectable stage II-IV cutaneous squamous cell carcinoma, neoadjuvant cemiplimab followed by surgery might be a potential treatment option, addressing a substantial unmet need.

FUNDING

Regeneron Pharmaceuticals and Sanofi.

Perioperative immunotherapy for esophageal squamous cell carcinoma: Now and future

Esophageal cancer (EC) ranks among the most prevalent malignant tumors affecting the digestive tract. Esophageal squamous cell carcinoma (ESCC) stands as the prevailing pathological subtype, encompassing approximately 90% of all EC patients. In clinical stage II-IVA locally advanced ESCC cases, the primary approach to treatment involves a combination of neoadjuvant therapy and surgical resection. Despite concerted efforts, the long-term outcomes for ESCC patients remain unsatisfactory, with dismal prognoses. However, recent years have witnessed remarkable strides in immunotherapy, particularly in the second- and first-line treatment of advanced or metastatic ESCC, with the development of monoclonal antibodies that inhibit programmed death 1 or programmed death ligand 1 demonstrating encouraging responses and perioperative clinical benefits for various malignancies, including ESCC. This comprehensive review aims to present the current landscape of perioperative immunotherapy for resectable ESCC, focusing specifically on the role of immune checkpoint inhibitors during the perioperative period. Additionally, the review will explore promising biomarkers and offer insights into future prospects.

From organ preservation to selective surgery: How immunotherapy changes colorectal surgery?

The emergence of immunotherapy has revolutionized the traditional treatment paradigm of colorectal cancer (CRC). Among them, immune checkpoint blockade has become the first-line treatment for metastatic colorectal cancer (mCRC) and has made significant progress in the treatment of locally advanced colorectal cancer (LACRC). We reviewed a series of clinical trials that have made breakthrough progress. We will emphasize the breakthrough progress in achieving organ preservation in patients with high microsatellite instability or DNA mismatch repair deficiency (MSI-H/dMMR), and based on this, we propose the concept of selective surgery, which includes selectively removing or preserving lymph nodes, with the aim of proving our idea through more research in the future.

Immunotherapy for Colorectal Cancer with High Microsatellite Instability: The Ongoing Search for Biomarkers

Microsatellite instability (MSI) is a biological condition associated with inflamed tumors, high tumor mutational burden (TMB), and responses to immune checkpoint inhibitors. In colorectal cancer (CRC), MSI tumors are found in 5% of patients in the metastatic setting and 15% in early-stage disease. Following the impressive clinical activity of immune checkpoint inhibitors in the metastatic setting, associated with deep and long-lasting responses, the development of immune checkpoint inhibitors has expanded to early-stage disease. Several phase II trials have demonstrated a high rate of pathological complete responses, with some patients even spared from surgery. However, in both settings, not all patients respond and some responses are short, emphasizing the importance of the ongoing search for accurate biomarkers. While various biomarkers of response have been evaluated in the context of MSI CRC, including B2M and JAK1/2 mutations, TMB, WNT pathway mutations, and Lynch syndrome, with mixed results, liver metastases have been associated with a lack of activity in such strategies. To improve patient selection and treatment outcomes, further research is required to identify additional biomarkers and refine existing ones. This will allow for the development of personalized treatment approaches and the integration of novel therapeutic strategies for MSI CRC patients with liver metastases.

Outcome of Patients With Early-Stage Mismatch Repair Deficient Colorectal Cancer Receiving Neoadjuvant Immunotherapy: A Systematic Review

PURPOSE

We conducted a systematic review to evaluate the outcome of patients with early-stage (stages I-III) mismatch repair deficient (dMMR) colorectal cancer (CRC) receiving neoadjuvant immunotherapy (NIT) with immune checkpoint inhibitor (ICI)-based regimens.

METHODS

MEDLINE, Scopus, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched for publications reporting the outcome of patients with early-stage dMMR CRC receiving NIT. The primary outcome measures were the complete response (CR) rate (clinical CR [cCR] or pathologic CR [pCR]) and the incidence of grade 3 or higher toxicities.

RESULTS

The search identified 37 publications that included 423 patients with colon (n = 326, 77%) and rectal (n = 97,23%) cancers aged 19-82 years; most patients had stage III CRC (88%). Approximately 67% of patients received monotherapy with anti-PD-1 agents; the rest received dual ICIs (ipilimumab plus nivolumab). The CR rate (pCR + cCR) in the overall population was 72% (305 of 423). The R0 resection and pCR rates were 99.3% and 70% among the patients undergoing surgery, respectively. Only four (0.9%) patients had primary resistance to NIT. After median follow-up periods ranging from 4 to 27 months, 3 (0.7%) patients progressed after an initial response. Grade 3 or higher toxicities were uncommon (6.3%), rarely delaying planned surgery.

CONCLUSION

NIT in patients with early-stage dMMR CRC is associated with a high response rate, low primary resistance to immunotherapy and cancer recurrence rate, and an excellent safety profile. The findings of the present systematic review support further investigation of NIT in patients with early-stage dMMR CRC, with a particular emphasis on the organ-preserving potential of this strategy.

Case Report: Systemic treatment for breast and vulvar metastases from resected rectal signet ring cell carcinoma

Background

Breast and vulvar metastases from rectal signet ring cell carcinoma (SRCC) represent a rare and obscure clinical entity associated with poor survival. Managing patients with metastatic rectal SRCC is extremely challenging due to the absence of high-quality evidence.

Case presentation

A 26-year-old woman presented with progressively worsening anal pain, constipation, and hematochezia for approximately two years. Following the diagnosis of locally advanced rectal cancer (_cT₃N_0-1M₀), she received neoadjuvant chemotherapy with modified FOLFOX6 regimen and underwent laparoscopic abdominoperineal resection. Metastases to the breast and vulva developed during postoperative chemotherapy. Genetic testing revealed RAS/BRAF wild-type and microsatellite instability (MSI)-low status. Though sequential administration of irinotecan plus tegafur and tegafur plus raltitrexed-based chemotherapy in combination with bevacizumab, the disease progressed rapidly. Sadly, the patient passed away 15 months after initial diagnosis due to rapidly progressive disease.

Conclusion

Rectal SRCC is associated with younger on-set, aggressive behaviors, and worse survival outcomes. Due to poor cohesiveness, SRCC tends to develop metastases. A patient's medical history and immunohistochemical staining (such as CK20, CK7, and CDX-2) can aid in identifying the tumor origin of breast and vulvar metastases. Mutations and signaling pathways predominant in the tumorigenesis of SRCC remains unveiled. There is poor effect of conventional chemotherapies, targeted and immunotherapies for colorectal adenocarcinoma on SRCC, so novel therapies are needed to treat this patient population.