Local Therapy for Oligoprogression or Consolidation in High Mutational Burden Stage 4 Colorectal Cancer Treated With PD-1 or PD-L1 Blockade.

BACKGROUND: Immune checkpoint blockade (ICI) of programmed cell death protein 1 (PD-1) or PD-1 ligand (PD-L1) can induce durable responses in patients who have colorectal cancer (CRC) with a high tumor mutational burden (TMB). Two recurring clinical dilemmas show how to manage oligoprogressive disease and stable disease after ICI. METHODS: A cohort study was conducted to analyze patients with metastatic CRC who underwent PD-1 or PD-L1 blockade. Tumors were mismatch repair (MMR) deficient or had more than 25 mutations per megabase. Patients were identified who had local therapy (surgery, ablation, or radiotherapy) for one to three sites of progressive disease (PD) or surgery to consolidate SD. The study evaluated clinical and biologic factors associated with patient selection, outcomes, and pathologic response rates. RESULTS: From 2014 to 2020, treatment was administered to 111 patients with ICI. Of these 111 patients, 19 (17%) survived fewer than 6 months, whereas to date, 50 have not had progression of disease. The remaining 42 patients experienced PD, and 16 (38%) were treated with local therapy for oligoprogression. Selection for local therapy was associated with response to ICI. The 2-year progression-free survival (PFS) after local therapy was 62%. Finally, 6 of the 50 patients without PD had consolidation of SD, and 5 had complete or near complete pathologic responses. CONCLUSIONS: Oligoprogression, a frequent pattern of failure after ICI, can be managed effectively with local therapy. In contrast, it may not be necessary to consolidate SD for selected patients. Further research is essential to define management algorithms better and to explore heterogeneity in response patterns.

Long-term Follow-up and Patterns of Response, Progression, and Hyperprogression in Patients after PD-1 Blockade in Advanced Sarcoma.

PURPOSE: Programmed cell death protein 1 (PD-1) blockade can mediate objective responses in advanced sarcomas, but their durability has not been established and it is unclear if hyperprogressive disease (HPD) occurs in sarcomas treated with PD-1 inhibitors. EXPERIMENTAL DESIGN: We pooled patients who were treated prospectively with nivolumab or pembrolizumab as monotherapy or with bempegaldesleukin, epacadostat, ipilimumab, or talimogene laherparepvec. We did a new independent assessment for HPD and analyzed clinical, pathologic, and genomic data from baseline tumor biopsies. Our primary endpoint was the incidence of HPD; secondary endpoints were clinical or genomic correlates of response or HPD. RESULTS: We treated 134 patients with advanced sarcoma from 2015 to 2019. Twenty-one patients (16%) had a complete or partial response (CR/PR), and 30% of responses were durable for over 2 years. Forty-eight (36%) patients had stable disease (SD), 45 (34%) had progressive disease without HPD (PD), and 15 (11%) had HPD. Five patients (4%) were not evaluable for HPD. The sarcoma subtypes, sites of metastasis, clinical course, and genomic alterations in patients with PD and HPD were similar, except HPD tumors were smaller at baseline. CONCLUSIONS: In patients with advanced sarcoma, PD-1 blockade can mediate durable responses. HPD occurs in sarcoma at an incidence that is similar to what has been reported in other solid tumors, but patients with HPD were clinically and biologically similar to those who had PD. Further research is required to establish whether HPD is a biologically distinct phenomenon and whether a theoretical risk of HPD should influence patient management.

Morbidity and Outcomes After Distal Pancreatectomy for Primary Retroperitoneal Sarcoma: An Analysis by the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group.

BACKGROUND: Multi-visceral resection often is used in the treatment of retroperitoneal sarcoma (RPS). The morbidity after distal pancreatectomy for primary pancreatic cancer is well-documented, but the outcomes after distal pancreatectomy for primary RPS are not. This study aimed to evaluate morbidity and oncologic outcomes after distal pancreatectomy for primary RPS. METHODS: In this study, 26 sarcoma centers that are members of the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) retrospectively identified consecutive patients who underwent distal pancreatectomy for primary RPS from 2008 to 2017. The outcomes measured were 90-day severe complications (Clavien-Dindo ≥ 3), postoperative pancreatic fistula (POPF) rate, and oncologic outcomes. RESULTS: Between 2008 and 2017, 280 patients underwent distal pancreatectomy for primary RPS. The median tumor size was 25 cm, and the median number of organs resected, including the pancreas, was three. In 96% of the operations, R0/R1 resection was achieved. The 90-day severe complication rate was 40 %. The grades B and C POPF complication rates were respectively 19% and 5% and not associated with worse overall survival. Administration of preoperative radiation and factors to mitigate POPF did not have an impact on the risk for the development of a POPF. The RPS invaded the pancreas in 38% of the patients, and local recurrence was doubled for the patients who had a microscopic, positive pancreas margin (hazard ratio, 2.0; p = 0.042). CONCLUSION: Distal pancreatectomy for primary RPS has acceptable morbidity and oncologic outcomes and is a reasonable approach to facilitate complete tumor resection.

The emerging role of immunotherapy for the treatment of sarcoma.

Clinicians caring for patients with sarcoma founded the field of cancer immunotherapy. Despite this, contemporary success with immunotherapy for sarcoma has been limited. Here, we review immunotherapy for sarcoma including Coley's toxins, interleukin-2, adoptive cell transfer, and checkpoint blockade. We detail recent and ongoing efforts to combine checkpoint blockade with other immune modulators, surgery, or radiation. These results, along with ongoing investigations, have identified immunotherapeutic approaches as a promising avenue for progress in advanced sarcomas.

Mortality risk associated with venous thromboembolism: a systematic review and Bayesian meta-analysis.

BACKGROUND: Venous thromboembolism is associated with increased mortality risk in some populations, but how frequently it is a direct cause of death is unclear. We used data from venous thromboembolism prevention trials to evaluate the causal effect of venous thromboembolism reduction on mortality. METHODS: We did a systematic review and meta-analysis of randomised controlled trials (RCTs) evaluating venous thromboembolism prevention. We searched MEDLINE, Embase, PubMed, and Web of Science starting from Jan 1, 1993, to March 19, 2018. We included studies of patients who were at elevated risk of venous thromboembolism and were randomly assigned to either anticoagulant or antiplatelet therapy versus placebo or no treatment. We excluded studies with an active control agent (which might mitigate the lethality of venous thromboembolism) and those for which mortality data were unavailable. We modelled heterogeneity in a Bayesian framework, taking overall mortality as a primary endpoint, and pulmonary embolism, fatal pulmonary embolism, and major bleeding as secondary endpoints. We focused our analyses on studies reporting statistically significant effects of prevention on venous thromboembolism endpoints. We report treatment effects as median risk ratios (RRs), wherein a null effect equals 1, with 95% credible intervals (CrIs). This meta-analysis was registered with PROSPERO, CRD42018089697. FINDINGS: From 4229 studies screened, we identified 86 eligible RCTs; 52, with data from over 70 000 patients, were positive, with significantly increased venous thromboembolism risk in patients in control groups versus treatment groups (RR 2·74, 95% CrI 2·32-3·31, p<0·0001). The meta-analysis established that the causal effect of venous thromboembolism prevention on mortality was null (control group mortality was 3391 [9·8%] of 34 537 patients; treatment group mortality was 3498 [9·8%] of 35 795 patients [RR 1·01, 95% CrI 0·97-1·06; p=0·58]) with low heterogeneity (τ 0·02, 95% CrI 0·00-0·07, p=0·89). Patients in control groups had more pulmonary embolism (RR 2·22, 95% CrI 1·78-2·89, p<0·0001) and fatal pulmonary embolism (1·58, 1·14-2·19, p=0·01), but less major bleeding (0·60, 0·47-0·75, p<0·0001) than those in treatment groups. A meta-analysis with the additional 34 negative studies yielded similar results for all endpoints except fatal pulmonary embolism, where evidence of an effect was weaker (1·42, 1·05-1·91, p=0·02). INTERPRETATION: The perception that venous thromboembolism is a common cause of mortality should be revised considering the null effect of venous thromboembolism prevention on mortality. Our findings call into question the use of composite endpoints in venous thromboembolism-prevention trials and provide rationale for de-escalation trials. FUNDING: None.

Survival after checkpoint inhibitors for metastatic acral, mucosal and uveal melanoma.

BACKGROUND: Checkpoint inhibitors (CPIs) are thought to be effective against cutaneous melanoma in part because of the large burden of somatic mutations (neoantigens) generated from exposure to ultraviolet radiation. However, rare melanoma subtypes arising from acral skin, mucosal surfaces, and the uveal tract are largely sun-shielded. Genomic studies show these sun-shielded melanomas have a paucity of neoantigens and unique biology; they are thought to be largely resistant to immunotherapy. It has not been definitively shown that CPI improves survival in metastatic sun-shielded melanoma. METHODS: We reviewed a single institutional experience using antibodies against CTLA-4, PD-1 and/or PD-L1 to treat patients with metastatic melanoma. Primary tumor histology was categorized as cutaneous, unknown, acral, mucosal, or uveal. We studied demographic data, treatment characteristics, and overall survival (OS) after CPI. RESULTS: We treated 428 patients with metastatic melanoma from 2007 to 2019. Primary tumors were cutaneous in 283 (66%), unknown in 55 (13%), acral in 22 (5%), mucosal in 38 (9%), and uveal in 30 (7%). Patients with metastatic disease from cutaneous primary tumors had median OS after CPI of 45 months compared with 17 months for acral (p=0.047), 18 months for mucosal (p=0.003), and 12 months for uveal (p<0.001). For all patients with sun-shielded melanoma (n=90), first treatment with anti-PD-1 or anti-PD-L1 was followed by a median OS of 9 months compared with 18 months after anti-CTLA-4 (p=0.010) and 20 months after combination therapy (p=0.003). There were 21 patients who achieved actual 3-year survival; 20 received both anti-CTLA-4 and anti-PD-1, either sequentially or in combination. Over 80% of 3-year survivors with progressive disease were treated with local therapy after CPI. CONCLUSIONS: Long survival in patients with metastatic melanoma from acral, mucosal, and uveal primary tumors was associated with receipt of both anti-CTLA-4 and anti-PD-1 antibodies. Complete responses were rare, and local therapy was frequently employed to control disease progression. While sun-shielded melanomas exhibit worse outcomes after CPI than cutaneous melanomas, with an aggressive multidisciplinary approach, 5-year survival is still possible for 25%-32% of these patients.

A Three-dimensional Thymic Culture System to Generate Murine Induced Pluripotent Stem Cell-derived Tumor Antigen-specific Thymic Emigrants.

The inheritance of pre-rearranged T cell receptors (TCRs) and their epigenetic rejuvenation make induced pluripotent stem cell (iPSC)-derived T cells a promising source for adoptive T cell therapy (ACT). However, classical in vitro methods for producing regenerated T cells from iPSC result in either innate-like or terminally differentiated T cells, which are phenotypically and functionally distinct from naïve T cells. Recently, a novel three-dimensional (3D) thymic culture system was developed to generate a homogenous subset of CD8αß+ antigen-specific T cells with a naïve T cell-like functional phenotype, including the capacity for proliferation, memory formation, and tumor suppression in vivo. This protocol avoids aberrant developmental fates, allowing for the generation of clinically relevant iPSC-derived T cells, designated as iPSC-derived thymic emigrants (iTE), while also providing a potent tool to elucidate the subsequent functions necessary for T cell maturation after thymic selection.

Patterns of failure after immunotherapy with checkpoint inhibitors predict durable progression-free survival after local therapy for metastatic melanoma.

BACKGROUND: Checkpoint inhibitors (CPI) have revolutionized the treatment of metastatic melanoma, but most patients treated with CPI eventually develop progressive disease. Local therapy including surgery, ablation or stereotactic body radiotherapy (SBRT) may be useful to manage limited progression, but criteria for patient selection have not been established. Previous work has suggested progression-free survival (PFS) after local therapy is associated with patterns of immunotherapy failure, but this has not been studied in patients treated with CPI. METHODS: We analyzed clinical data from patients with metastatic melanoma who were treated with antibodies against CTLA-4, PD-1 or PD-L1, either as single-agent or combination therapy, and identified those who had disease progression in 1 to 3 sites managed with local therapy. Patterns of CPI failure were designated by independent radiological review as growth of established metastases or appearance of new metastases. Local therapy for diagnosis, palliation or CNS metastases was excluded. RESULTS: Four hundred twenty-eight patients with metastatic melanoma received treatment with CPI from 2007 to 2018. Seventy-seven have ongoing complete responses while 69 died within 6 months of starting CPI; of the remaining 282 patients, 52 (18%) were treated with local therapy meeting our inclusion criteria. Local therapy to achieve no evidence of disease (NED) was associated with three-year progression-free survival (PFS) of 31% and five-year disease-specific survival (DSS) of 60%. Stratified by patterns of failure, patients with progression in established tumors had three-year PFS of 70%, while those with new metastases had three-year PFS of 6% (P = 0.001). Five-year DSS after local therapy was 93% versus 31%, respectively (P = 0.046). CONCLUSIONS: Local therapy for oligoprogression after CPI can result in durable PFS in selected patients. We observed that patterns of failure seen during or after CPI treatment are strongly associated with PFS after local therapy, and may represent a useful criterion for patient selection. This experience suggests there may be an increased role for local therapy in patients being treated with immunotherapy.

Role of Surgery in Combination with Immunotherapy.

Improvements in systemic immunotherapy are changing the treatment of patients with advanced melanoma and many other tumors. Surgeons may be increasingly called on to manage isolated sites of immunorefractory disease or to provide palliative surgery as a bridge to systemic therapy. Here, the authors describe the biologic rationale for using surgery in patients with immunorefractory disease, provide background on the evolving role of metastasectomy for advanced melanoma, and summarize data on the use of neoadjuvant immunotherapy. Finally, the authors discuss the direction of clinical research in this rapidly evolving field.

Completion lymphadenectomy for a positive sentinel node biopsy in melanoma patients is not associated with a survival benefit.

BACKGROUND: Completion lymph node dissection (CLND) for sentinel lymph node (SLN) disease in melanoma patients is debated. We evaluated the impact of CLND on survival and assessed for predictors of nonsentinel node metastasis (positive CLND). METHODS: Positive SLN melanoma patients were retrospectively identified in the Sentinel Lymph Node Working Group database. Clinicopathological factors were correlated with CLND status, overall survival (OS), and melanoma-specific survival (MSS). RESULTS: There were 953 positive SLN patients of whom 831 (87%) had CLND. Positive CLND was seen in 141 (17%) cases and was associated with worse OS and MSS (both P < 0.001). CLND was not performed (No-CLND) in 122 of 953 positive SLN cases (13%), of whom 100 had follow-up and 18 (18%) developed a nodal recurrence (NR). No significant differences in OS and MSS were seen comparing CLND with No-CLND (P = 0.084, P = 0.161, respectively) and comparing positive CLND with No-CLND NR patients (P = 0.565, P = 0.998, respectively). Gender, primary site, ulceration, and number of positive SLNs were correlated with nonsentinel node metastasis. CONCLUSIONS: Performance of CLND provides prognostic information but is not associated with a survival benefit. Clinical variables can predict a positive CLND in patients who may be at high risk of recurrence.

Generation of Tumor Antigen-Specific iPSC-Derived Thymic Emigrants Using a 3D Thymic Culture System.

Induced pluripotent stem cell (iPSC)-derived T cells may provide future therapies for cancer patients, but those generated by current methods, such as the OP9/DLL1 system, have shown abnormalities that pose major barriers for clinical translation. Our data indicate that these iPSC-derived CD8 single-positive T cells are more like CD4+CD8+ double-positive T cells than mature naive T cells because they display phenotypic markers of developmental arrest and an innate-like phenotype after stimulation. We developed a 3D thymic culture system to avoid these aberrant developmental fates, generating a homogeneous subset of CD8αß+ antigen-specific T cells, designated iPSC-derived thymic emigrants (iTEs). iTEs exhibit phenotypic and functional similarities to naive T cells both in vitro and in vivo, including the capacity for expansion, memory formation, and tumor suppression. These data illustrate the limitations of current methods and provide a tool to develop the next generation of iPSC-based antigen-specific immunotherapies.

Correction to: Metastasectomy for Tumor-Infiltrating Lymphocytes: An Emerging Operative Indication in Surgical Oncology.

In the original article the middle initial of Nicholas D. Klemen was inadvertently omitted. On the first page of the original article, under the heading A Novel Way to Fight Cancer, there was an error in the third sentence. The corrected text is as follows: For example, the presence of T cells within tumors of colorectal origin can be a superior predictor of patient survival compared with the standard histopathologic methods currently used to stage colorectal cancer.6,7.

Metastasectomy for Tumor-Infiltrating Lymphocytes: An Emerging Operative Indication in Surgical Oncology.

Adoptive cell transfer (ACT) of tumor-infiltrating lymphocytes (TILs) is an emerging immunotherapy for metastatic cancer. Surgeons play a central role in ACT treatments by performing resection of tumors from which TILs are isolated. It is important that surgeons have familiarity with this emerging treatment method because it is increasingly performed for an expanding variety of solid tumors at institutions around the world. This report offers a brief introduction to ACT for cancer, highlights historical milestones in its development, and provides patient selection and operative considerations for surgeons called upon to perform metastasectomy for the purpose of isolating TILs.

Adjuvant intraperitoneal chemotherapy for the treatment of colorectal cancer at risk for peritoneal carcinomatosis: a systematic review.

BACKGROUND: The peritoneal surface is the second most common site of disease recurrence, after the liver, following definitive surgery for colorectal cancer. Adjuvant intraperitoneal (IP) chemotherapy delivered at time of surgical resection has the potential to delay or prevent future spread to the peritoneal surface and improve clinical outcome. The exact role of adjuvant IP chemotherapy in colorectal cancer, including its associated morbidity and mortality, is not well defined. STUDY DESIGN: Systematic review and pooled random effect analysis of comparative trials examining the addition of adjuvant IP chemotherapy compared to surgery alone in colorectal cancer. The primary outcome was overall survival, and the secondary outcomes were of post-operative morbidity and mortality. RESULTS: In nine colorectal cancer studies identified, seven were two-arm trials comparing adjuvant IP chemotherapy to surgery alone. Of these, four trials had outcome reporting and met criteria that allowed inclusion into a random effects model. Heterogeneity was measured by Cochran's Q-test (Q = 13.9; p = 0.01) and random effect models were utilised. Pooling eligible trials together revealed a 0.55 odds ratio of death associated with the administration of IP chemotherapy compared to surgery alone (CI = 0.31, 0.98; p = 0.04). Trials selecting patients at elevated risk for the development of peritoneal carcinomatosis by clinicopathological biomarkers for administration of adjuvant IP chemotherapy reported more favourable overall outcomes. There was no increase in mortalities or IP chemotherapy-related abdominal complication rates among patients undergoing IP chemotherapy (OR = 1.4; CI = 0.52, 3.8; p = 0.5). CONCLUSIONS: This systematic review supports the use of adjuvant IP chemotherapy in resectable colorectal cancer at risk for peritoneal spread. Future trials should seek to standardise inclusion criteria and IP chemotherapy modalities to better define the role of this treatment in patients with resectable colorectal cancer.