Pathological response and tumour bed histopathological features correlate with survival following neoadjuvant immunotherapy in stage III melanoma

Neoadjuvant Therapy: Changes in the Management of Macroscopic Stage III/Resectable Stage IV Melanoma

Existing adjuvant therapies improve outcomes for resected stage III and IV melanoma patients but fail in almost half to prevent recurrence and death. Large, multi-institution, randomized studies firmly establish the superiority of neoadjuvant to adjuvant therapy alone. Checkpoint inhibition, either anti-programmed cell death protein 1 monotherapy or combination with CTLA-4/LAG-3 blockage, demonstrates more durable event-free survival compared to targeted or targeted/immunotherapy combination therapies. Novel combinations of intralesional immunotherapies and other agents aim to increase clinical efficacy and limit toxicity of therapies. Pathologic response to treatment remains as the best prognostic surrogate for clinical outcomes for patients.

18F-FDG Versus 68Ga-FAPI PET/MRI Findings in a Case of Primary Gastric Melanoma

Primary gastric melanoma has an extremely low incidence. In this case, we describe the 18F-FDG and 68Ga-FAPI PET/MRI findings in a 43-year-old patient with primary gastric melanoma. The imaging revealed heterogeneous patterns between 18F-FDG and 68Ga-FAPI PET/MRI, emphasizing the complementary roles of dual-tracer imaging in characterizing tumor characteristics of primary gastric melanoma.

Longitudinal Analysis Reveals Dynamic Changes in Histopathologic Features in Responders to Neoadjuvant Treatment in a Stage III BRAF-Mutant Melanoma Cohort

Despite advances in systemic therapies, cutaneous melanoma remains a highly deadly disease. Patients with high-risk stage III melanoma have a significant likelihood of recurrence following surgery. Although adjuvant immunotherapy has been the standard of care, recent evidence demonstrates that neoadjuvant immunotherapy is more effective for higher-risk stage III patients, showing superior survival outcomes compared with adjuvant immunotherapy. This has led to an immediate paradigm shift in clinical practice toward neoadjuvant therapy for this cohort. The NeoTrio clinical trial assessed the efficacy of sequential or combination BRAF-targeted therapy with anti-programmed cell death-1 in the neoadjuvant setting. However, research on longitudinal histopathologic changes during this treatment period remains limited. Analysis of hematoxylin and eosin slides from 60 patients across 4 matched neoadjuvant timepoints revealed dynamic changes in a number of treatment response features. Females achieved significantly higher rates of major pathologic response (P = .002) and displayed higher levels of inflammatory fibrosis (P = .04) and hyalinized fibrosis (P = .01). The presence of tertiary lymphoid structures (P = .013) and plasma cells (P = .02) at resection was significantly associated with response. Combination scoring of histopathologic features (composite score and the immune-related pathologic response [irPR] score) was significantly associated with response early during the neoadjuvant period (composite score at week 2 on-treatment, P = .03; high irPR score at week 2 on-treatment, P = .01). A high irPR score at week 2 on-treatment was also found to be significantly associated with a lower chance of recurrence at this early neoadjuvant timepoint (P = .02). Other features associated with a lower likelihood of recurrence included increased hyalinized fibrosis (P = .015) and the presence of extensive lymphocyte density score (P = .01), tertiary lymphoid structures (P = .03), and plasma cells (P = .01). This study deepens our understanding of treatment response markers and their dynamic changes during neoadjuvant therapy. It underscores the significance of these features, particularly given their early emergence and strong associations with response and recurrence.

Neoadjuvant Therapy and Lung Cancer: Role of Pathologists

CONTEXT.—

Recent neoadjuvant clinical trials in lung cancer have demonstrated the survival benefits in carefully selected patients. Standardization of the assessment of pathologic response to neoadjuvant therapy in surgically resected specimens is required.

OBJECTIVE.—

To review the current pathology practices in the gross processing and microscopic assessment of surgically resected non-small cell lung carcinoma specimens after neoadjuvant therapy.

DATA SOURCES.—

PubMed publications and experience of the author.

CONCLUSIONS.—

Gross processing of the surgically resected lung carcinoma after neoadjuvant therapy needs further refinement and standardization in clinical trials and in a real-world clinical practice. Microscopic assessment of the response includes quantification of viable tumor, necrosis, and stroma. The best approach would be to use a single standardized and most reproducible scoring system. Published studies on gross processing of lung carcinoma specimens in the neoadjuvant setting and microscopic assessment of pathologic response provide a good foundation for the future standardization of pathology practice.

Opportunities for Discovery Using Neoadjuvant Immune Checkpoint Blockade in Melanoma

Treatment of resectable advanced-stage melanoma with neoadjuvant immunotherapy is rapidly becoming the new standard of care due to significant improvements in event-free survival (EFS) compared to surgery first followed by immunotherapy. The level of responsiveness seen in patients receiving immune checkpoint inhibitors (ICIs) must be mechanistically understood not only for the standardization of treatment but also to advance the novel concept of personalized cancer immunotherapy. This review aims to elucidate markers of the tumor microenvironment (TME) and blood that can predict treatment outcome. Interestingly, the canonical proteins involved in the molecular interactions that immunotherapies aim to disrupt have not been consistent indicators of treatment response, which amplifies the necessity for further research on the predictive model. Other major discussions surrounding neoadjuvant therapy involve the higher-level investigation of ICI efficacy due to the ability to examine a post-treatment tumor molecularly and pathologically, which this review will also cover. As neoadjuvant ICI becomes the standard of care in advanced melanoma treatment, further research aiming to identify more predictive biomarkers of treatment response to advance medical decision-making and patient care should continue to be sought after.

Histopathologic and Molecular Insights Following the Management of Ameloblastomas via Targeted Therapies - Pathological and Clinical Perspectives

PURPOSE

Current standard of care for ameloblastoma (conventional/unicystic - mural type) usually mandates extensive bone resection that frequently necessitates immediate reconstruction with serious sequelae, especially among young patients. BRAF-mutated ameloblastomas can be targeted by BRAF inhibitors to markedly reduce their size, enabling conservative removal of residual tumor. We aimed to characterize the effect of post-treatment histomorphologic changes.

METHODS

Study included 14 patients, 11 mandibular and three maxillary tumors. Cases with very minimal residual tumor were defined as near-complete response, while those with mostly vital residual tumor as partial response. The epithelium component was scored for architectural and cellular changes, stroma - for fibrosis, inflammation and new bone formation, on a 3-tired score system: 0-no, 1-focal and 3-frequent changes. The mean scores of each parameter, total epithelium and total stroma were calculated and related to duration of treatment. Differences in the mean scores were investigated for mandibular tumors with near-complete response (n = 3) and partial response (n = 8).

RESULTS

There were no significant differences in mean epithelium or stroma scores between tumors with near-complete and those with partial response (2.22 ± 0.68 versus 2.08 ± 0.43, p = 0.55; 1.41 ± 1.04 versus 1.43 ± 0.44, p = 0.27), suggesting that ameloblastomas have potential to undergo complete response to targeted treatment. This is probably dependent upon tumor/patient/treatment-related factors. Response to treatment appears to be predictable with neoplastic epithelium being first, while the stromal response increases during treatment, the entire process expanding over weeks-to-months.

CONCLUSION

Albeit preliminary, these are the first comprehensive histomorphologic findings on BRAF-treated ameloblastomas. Analyzing the suggested parameters in tumors with partial response, should highlight which tumor component has responded/failed to respond. This could serve as a basis for decision-taking toward subsequent steps in adjuvant treatment (e.g., follow-up, conservative surgery, modifications/changes in treatment regimen, combinations of approaches), with a prime aim of jaw preservation and minimal risk of sequelae.

Neoadjuvant immunotherapy for dMMR and pMMR colorectal cancers: therapeutic strategies and putative biomarkers of response

Approximately 15% of locally advanced colorectal cancers (CRC) have DNA mismatch repair deficiency (dMMR), resulting in high microsatellite instability and a high tumour mutational burden. These cancers are frequently sensitive to therapy with immune-checkpoint inhibitors (ICIs) in the metastatic setting. This sensitivity seems to be even more pronounced in locally advanced disease, and organ preservation has become a realistic aim in ongoing clinical trials involving patients with dMMR rectal cancer. By contrast, metastatic CRCs with proficient DNA mismatch repair (pMMR) are generally resistant to ICIs, although a proportion of locally advanced pMMR tumours seem to have a high degree of sensitivity to ICIs. In this Review, we describe the current and emerging clinical evidence supporting the use of neoadjuvant ICIs in patients with dMMR and pMMR CRC, and the potential advantages (based on a biological rationale) of such an approach. We discuss how neoadjuvant 'window-of-opportunity' trials are being leveraged to progress biomarker discovery and we provide an overview of potential predictive biomarkers of response to ICIs, exploring the challenges faced when evaluating such biomarkers in biopsy-derived samples. Lastly, we describe how these discoveries might be used to drive a rational approach to trialling novel immunotherapeutic strategies in patients with pMMR CRC, with the ultimate aim of disease eradication and the generation of long-term immunosurveillance.

Neoadjuvant vidutolimod and nivolumab in high-risk resectable melanoma: A prospective phase II trial

Intratumoral TLR9 agonists and anti-PD-1 produce clinical responses and broad immune activation. We conducted a single-arm study of neoadjuvant TLR9 agonist vidutolimod combined with anti-PD-1 nivolumab in high-risk resectable melanoma. In 31 evaluable patients, 55% major pathologic response (MPR) was observed, meeting primary endpoint. MPR was associated with necrosis, and melanophagocytosis with increased CD8+ tumor-infiltrating lymphocytes and plasmacytoid dendritic cells (pDCs) in the tumor microenvironment, and increased frequencies of Ki67+CD8+ T cells peripherally. MPRs had an enriched pre-treatment gene signature of myeloid cells, and response to therapy was associated with gene signatures of immune cells, pDCs, phagocytosis, and macrophage activation. MPRs gut microbiota were enriched for Gram-negative bacteria belonging to the Bacteroidaceae and Enterobacteriaceae families and the small subgroup of Gram-negative Firmicutes. Our findings support that combined vidutolimod and nivolumab stimulates a broad anti-tumor immune response and is associated with distinct baseline myeloid gene signature and gut microbiota. ClinicalTrials.gov identifier: NCT03618641.

Tumor-Infiltrating Lymphocytes in Necrotic Tumors after Melanoma Neoadjuvant Anti-PD-1 Therapy Correlate with Pathologic Response and Recurrence-Free Survival

PURPOSE

Neoadjuvant anti-PD-1 therapy in melanoma may increase tumor-infiltrating lymphocytes (TIL), and more TIL are associated with better treatment response. A major pathologic response (MPR) in melanoma after neoadjuvant anti-PD-1 therapy usually comprises tumor necrosis and fibrosis. The role of TIL in necrotic tumor necrosis (nTIL) has not been explored.

EXPERIMENTAL DESIGN

We performed CD3 and CD8 IHC stains on 41 melanomas with geographic necrosis. Of the 41, 14 were immunotherapy-naïve, and 27 had been treated with one dose of neoadjuvant anti-PD-1 in two clinical trials. CD3+ and CD8+ nTIL were graded as absent/minimal or moderate/brisk. The percentage of necrotic areas in the tumor bed before and after treatment was quantified. The endpoints were MPR and 5-year recurrence-free survival (RFS).

RESULTS

In the immunotherapy-naïve cohort, 3/14 (21%) specimens had moderate/brisk CD3+, and 2/14 (14%) had moderate/brisk CD8+ nTIL. In the treated cohort, 16/27 (59%) specimens had moderate/brisk CD3+, and 15/27 (56%) had moderate/brisk CD8+ nTIL, higher than those of the naïve cohort (CD3, P = 0.046; CD8, P = 0.018). Tumor necrosis was significantly increased after anti-PD-1 therapy (P = 0.007). In the treated cohort, moderate/brisk CD3+ and CD8+ nTIL correlated with MPR (P = 0.042; P = 0.019, respectively). Treated patients with moderate/brisk CD3+ nTIL had higher 5-year RFS than those with absent/minimal nTIL (69% vs. 0%; P = 0.006). This persisted on multivariate analysis (HR, 0.16; 95% confidence interval, 0.03-0.84; P = 0.03), adjusted for pathologic response, which was borderline significant (HR, 0.26; 95% confidence interval, 0.07-1.01; P = 0.051).

CONCLUSIONS

CD3+ and CD8+ nTIL are associated with pathologic response and 5-year RFS in patients with melanoma after neoadjuvant anti-PD-1 therapy.

The Prognostic Significance of Tumoral Melanosis

BACKGROUND

Tumoral melanosis (TM) is a histological term to describe a nodular aggregation of macrophages containing melanin pigment (melanophages) that is devoid of viable melanocytes. It is most often identified in skin, where it may be appreciated clinically as a pigmented lesion; however, it can also be found in other organs such as lymph nodes. The presence of TM is usually thought to signify the presence of a regressed melanoma or other pigmented tumor. Until recently, it was a relatively uncommon finding; however, with the use of effective systemic therapies against melanoma, its occurrence in histological specimens is more frequent.

METHODS

We identified and reviewed all histopathological diagnoses of TM at any organ site reported at a single institution from 2006 to 2018. TM cases were paired with non-TM cases of cutaneous melanoma through propensity score matching at a 1:2 ratio, and their survival outcomes were compared. The clinical outcomes examined included recurrence-free survival (RFS), distant disease-free survival (DDFS), melanoma-specific survival (MSS), and overall survival (OS).

RESULTS

TM was reported in 79 patients. Their median age was 65 years (range 22-88), with a 2:1 male predominance (51 out of 79, 65%). The most common organ involved was the skin (67%), with a third of all cases localized to a lower limb (36%). TM had a strong association with the presence of melanoma (91%) and regression at other sites of melanoma (54%), suggesting that it is part of a systemic immune response against melanoma. Most patients with TM either previously or subsequently developed histologically confirmed melanoma in the same anatomical region as the TM (89%). Thirty-five TM patients were matched with 70 non-TM cases. Patients with melanoma who developed TM without prior regional or systemic therapy showed improved MSS (p = 0.03), whereas no statistically significant differences were observed in terms of RFS, DDFS, and OS.

CONCLUSIONS

TM usually occurs in the context of a previous or subsequent cutaneous melanoma and is associated with improved MSS. It is important that TM is recognized by pathologists and documented in pathology reports.

Advancements in neoadjuvant immune checkpoint inhibitor therapy for locally advanced head and neck squamous Carcinoma: A narrative review

The prevalent treatment paradigm for locally advanced head and neck squamous carcinoma (HNSCC) typically entails surgery followed by adjuvant radiotherapy and chemotherapy. Despite this, a significant proportion of patients experience recurrence and metastasis. Immune checkpoint inhibitors (ICIs), notably pembrolizumab and nivolumab, have been established as the first and second lines of treatment for recurrent and metastatic HNSCC (R/M HNSCC). The application of ICIs as neoadjuvant immunotherapy in this context is currently under rigorous investigation. This review synthesizes data from clinical trials focusing on neoadjuvant ICIs, highlighting that the pathological responses elicited by these treatments are promising. Furthermore, it is noted that the safety profiles of both monotherapy and combination therapies with ICIs are manageable, with no new safety signals identified. The review concludes by contemplating the future direction and challenges associated with neoadjuvant ICI therapy, encompassing aspects such as the refinement of imaging and pathological response criteria, selection criteria for adjuvant therapies, evaluation of the efficacy and safety of various combination treatment modalities, and the identification of responsive patient cohorts.

Prognostic biomarkers in melanoma: a 2023 update from clinical trials in different therapeutic scenarios

INTRODUCTION

Over the past decade, significant advancements in the field of melanoma have included the introduction of a new staging system and the development of immunotherapy and targeted therapies, leading to changes in substage classification and impacting patient prognosis. Despite these strides, early detection remains paramount. The quest for dependable prognostic biomarkers is ongoing, given melanoma's unpredictable nature, especially in identifying patients at risk of relapse. Reliable biomarkers are critical for informed treatment decisions.

AREAS COVERED

This review offers a comprehensive review of prognostic biomarkers in the context of clinical trials for immunotherapy and targeted therapy. It explores different clinical scenarios, including adjuvant, metastatic, and neo-adjuvant settings. Key findings suggest that tumor mutational burden, PD-L1 expression, IFN-γ signature, and immune-related factors are promising biomarkers associated with improved treatment responses.

EXPERT OPINION

Identifying practical prognostic factors for melanoma therapy is challenging due to the tumor's heterogeneity. Promising biomarkers include tumor mutational burden (TMB), circulating tumor DNA, and those characterizing the tumor microenvironment, especially the immune component. Future research should prioritize large-scale, prospective studies to validate and standardize these biomarkers, emphasizing clinical relevance and real-world applicability. Easily accessible biomarkers have the potential to enhance the precision and effectiveness of melanoma management.

Society for Immunotherapy of Cancer (SITC) recommendations on intratumoral immunotherapy clinical trials (IICT): from premalignant to metastatic disease

BACKGROUND

Intratumorally delivered immunotherapies have the potential to favorably alter the local tumor microenvironment and may stimulate systemic host immunity, offering an alternative or adjunct to other local and systemic treatments. Despite their potential, these therapies have had limited success in late-phase trials for advanced cancer resulting in few formal approvals. The Society for Immunotherapy of Cancer (SITC) convened a panel of experts to determine how to design clinical trials with the greatest chance of demonstrating the benefits of intratumoral immunotherapy for patients with cancers across all stages of pathogenesis.

METHODS

An Intratumoral Immunotherapy Clinical Trials Expert Panel composed of international key stakeholders from academia and industry was assembled. A multiple choice/free response survey was distributed to the panel, and the results of this survey were discussed during a half-day consensus meeting. Key discussion points are summarized in the following manuscript.

RESULTS

The panel determined unique clinical trial designs tailored to different stages of cancer development-from premalignant to unresectable/metastatic-that can maximize the chance of capturing the effect of intratumoral immunotherapies. Design elements discussed included study type, patient stratification and exclusion criteria, indications of randomization, study arm determination, endpoints, biological sample collection, and response assessment with biomarkers and imaging. Populations to prioritize for the study of intratumoral immunotherapy, including stage, type of cancer and line of treatment, were also discussed along with common barriers to the development of these local treatments.

CONCLUSIONS

The SITC Intratumoral Immunotherapy Clinical Trials Expert Panel has identified key considerations for the design and implementation of studies that have the greatest potential to capture the effect of intratumorally delivered immunotherapies. With more effective and standardized trial designs, the potential of intratumoral immunotherapy can be realized and lead to regulatory approvals that will extend the benefit of these local treatments to the patients who need them the most.

Neo-Adjuvant Therapy for Metastatic Melanoma

Melanoma treatment is leading the neo-adjuvant systemic (NAS) therapy field. It is hypothesized that having the entire tumor in situ, with all of the heterogeneous tumor antigens, allows the patient's immune system to have a broader response to the tumor in all its shapes and forms. This translates into a higher clinical efficacy. Another benefit of NAS therapy potentially includes identifying patients who have a favorable response, which could offer an opportunity for the de-escalation of the extent of surgery and the need for adjuvant radiotherapy and/or adjuvant systemic therapy, as well as tailoring the follow-up in terms of the frequency of visits and cross-sectional imaging. In this paper, we will review the rationale for NAS therapy in resectable metastatic melanoma and the results obtained so far, both for immunotherapy and for BRAF/MEKi therapy, and discuss the response assessment and interpretation, toxicity and surgical considerations. All the trials that have been reported up to now have been investigator-initiated phase I/II trials with either single-agent anti-PD-1, combination anti-CTLA-4 and anti-PD-1 or BRAF/MEK inhibition. The results have been good but are especially encouraging for immunotherapies, showing high durable recurrence-free survival rates. Combination immunotherapy seems superior, with a higher rate of pathologic responses, particularly in patients with a major pathologic response (MPR = pathologic complete response [pCR] + near-pCR [max 10% viable tumor cells]) of 60% vs. 25-30%. The SWOG S1801 trial has recently shown a 23% improvement in event-free survival (EFS) after 2 years for pembrolizumab when giving 3 doses as NAS therapy and 15 as adjuvant versus 18 as adjuvant only. The community is keen to see the first results (expected in 2024) of the phase 3 NADINA trial (NCT04949113), which randomized patients between surgery + adjuvant anti-PD-1 and two NAS therapy courses of a combination of ipilimumab + nivolumab, followed by surgery and a response-driven adjuvant regimen or follow-up. We are on the eve of neo-adjuvant systemic (NAS) therapy, particularly immunotherapy, becoming the novel standard of care for macroscopic stage III melanoma.

Perioperative therapy of melanoma: Adjuvant or neoadjuvant treatment

Surgery is the mainstay treatment of melanoma. However, even after radical resection the risk of relapses in majority of stage IIB-IV disease remains high. Currently, the standard treatment after surgery in high risk patients is systemic adjuvant therapy administered up to one year based on the results of clinical trials indicating significant reduction of risk of relapses. All clinical trials in adjuvant setting were based as primary end-point on relapse-free survival, not overall survival, and they did not incorporate and validate biomarkers prospectively. A new therapeutic strategy in locoregional advanced melanomas becomes a preoperative treatment to further increase of the cure rates and decrease the duration of systemic therapy.

Prognostic and predictive biomarkers in melanoma

Biomarkers help to inform the clinical management of patients with melanoma. For patients with clinically localised primary melanoma, biomarkers can help to predict post-surgical outcome (including via the use of risk prediction tools), better select patients for sentinel lymph node biopsy, and tailor catch-all follow-up protocols to the individual. Systemic drug treatments, including immune checkpoint inhibitor (ICI) therapies and BRAF-targeted therapies, have radically improved the prognosis of metastatic (stage III and IV) cutaneous melanoma patients, and also shown benefit in the earlier setting of stage IIB/C primary melanoma. Unfortunately, a response is far from guaranteed. Here, we review clinically relevant, established, and emerging, prognostic, and predictive pathological biomarkers that refine clinical decision-making in primary and metastatic melanoma patients. Gene expression profile assays and nomograms are emerging tools for prognostication and sentinel lymph node risk prediction in primary melanoma patients. Biomarkers incorporated into clinical practice guidelines include BRAF V600 mutations for the use of targeted therapies in metastatic cutaneous melanoma, and the HLA-A∗02:01 allele for the use of a bispecific fusion protein in metastatic uveal melanoma. Several predictive biomarkers have been proposed for ICI therapies but have not been incorporated into Australian clinical practice guidelines. Further research, validation, and assessment of clinical utility is required before more prognostic and predictive biomarkers are fluidly integrated into routine care.

Addressing Genetic Tumor Heterogeneity, Post-Therapy Metastatic Spread, Cancer Repopulation, and Development of Acquired Tumor Cell Resistance

The concept of post-therapy metastatic spread, cancer repopulation and acquired tumor cell resistance (M-CRAC) rationalizes tumor progression because of tumor cell heterogeneity arising from post-therapy genetic damage and subsequent tissue repair mechanisms. Therapeutic strategies designed to specifically address M-CRAC involve tissue editing approaches, such as low-dose metronomic chemotherapy and the use of transcriptional modulators with or without targeted therapies. Notably, tumor tissue editing holds the potential to treat patients, who are refractory to or relapsing (r/r) after conventional chemotherapy, which is usually based on administering a maximum tolerable dose of a cytostatic drugs. Clinical trials enrolling patients with r/r malignancies, e.g., non-small cell lung cancer, Hodgkin's lymphoma, Langerhans cell histiocytosis and acute myelocytic leukemia, indicate that tissue editing approaches could yield tangible clinical benefit. In contrast to conventional chemotherapy or state-of-the-art precision medicine, tissue editing employs a multi-pronged approach targeting important drivers of M-CRAC across various tumor entities, thereby, simultaneously engaging tumor cell differentiation, immunomodulation, and inflammation control. In this review, we highlight the M-CRAC concept as a major factor in resistance to conventional cancer therapies and discusses tissue editing as a potential treatment.

International Association for the Study of Lung Cancer Study of Reproducibility in Assessment of Pathologic Response in Resected Lung Cancers After Neoadjuvant Therapy

INTRODUCTION

Pathologic response has been proposed as an early clinical trial end point of survival after neoadjuvant treatment in clinical trials of NSCLC. The International Association for the Study of Lung Cancer (IASLC) published recommendations for pathologic evaluation of resected lung cancers after neoadjuvant therapy. The aim of this study was to assess pathologic response interobserver reproducibility using IASLC criteria.

METHODS

An international panel of 11 pulmonary pathologists reviewed hematoxylin and eosin-stained slides from the lung tumors of resected NSCLC from 84 patients who received neoadjuvant immune checkpoint inhibitors in six clinical trials. Pathologic response was assessed for percent viable tumor, necrosis, and stroma. For each slide, tumor bed area was measured microscopically, and pre-embedded formulas calculated unweighted and weighted major pathologic response (MPR) averages to reflect variable tumor bed proportion.

RESULTS

Unanimous agreement among pathologists for MPR was observed in 68 patients (81%), and inter-rater agreement (IRA) was 0.84 (95% confidence interval [CI]: 0.76-0.92) and 0.86 (95% CI: 0.79-0.93) for unweighted and weighted averages, respectively. Overall, unweighted and weighted methods did not reveal significant differences in the classification of MPR. The highest concordance by both methods was observed for cases with more than 95% viable tumor (IRA = 0.98, 95% CI: 0.96-1) and 0% viable tumor (IRA = 0.94, 95% CI: 0.89-0.98). The most common reasons for discrepancies included interpretations of tumor bed, presence of prominent stromal inflammation, distinction between reactive and neoplastic pneumocytes, and assessment of invasive mucinous adenocarcinoma.

CONCLUSIONS

Our study revealed excellent reliability in cases with no residual viable tumor and good reliability for MPR with the IASLC recommended less than or equal to 10% cutoff for viable tumor after neoadjuvant therapy.

Primary resistance to nivolumab plus ipilimumab therapy in patients with metastatic renal cell carcinoma

BACKGROUND

Nivolumab plus ipilimumab (NIVO+IPI) is the first-line treatment for patients with metastatic renal cell carcinoma (mRCC). Approximately 40% of patients achieve a durable response; however, 20% develop primary resistant disease (PRD) to NIVO+IPI, about which little is known in patients with mRCC. Therefore, this investigation aimed to evaluate the clinical implication of PRD in patients with mRCC to select better candidates in whom NIVO+IPI can be initiated as first-line therapy.

METHODS

This multi-institutional retrospective cohort study used data collected between August 2015 and January 2023. In total, 120 patients with mRCC treated with NIVO+IPI were eligible. Associations between immune-related adverse events and progression-free survival, overall survival (OS), and objective response rate were analyzed. The relationship between other clinical factors and outcomes was also evaluated.

RESULTS

The median observation period was 16 months (interquartile range, 5-27). The median age at NIVO+IPI initiation was 68 years in the male-dominant population (n = 86, 71.7%), and most patients had clear cell histology (n = 104, 86.7%). PRD was recorded in 26 (23.4%) of 111 investigated patients during NIVO+IPI therapy. Patients who experienced PRD showed worse OS (hazard ratio: 4.525, 95% confidence interval [CI]: 2.315-8.850, p < 0.001). Multivariable analysis showed that lymph node metastasis (LNM) (odds ratio: 4.274, 95% CI: 1.075-16.949, p = 0.039) was an independent risk factor for PRD.

CONCLUSIONS

PRD was strongly correlated with worse survival rates. LNM was independently associated with PRD in patients with mRCC receiving NIVO+IPI as first-line therapy and might indicate that a candidate will not benefit from NIVO+IPI.

Malignant Melanoma of the External Auditory Canal on 68 Ga-FAPI PET/CT

ABSTRACT

External ear melanomas are relatively rare and usually occur in the regions of helix and ear lobes. Rarer still are primary melanomas of the external auditory canal. We report findings of melanoma of the external auditory canal on 68 Ga-FAPI PET/CT in a 56-year-old man who presented with sharp pain in the external auditory canal for 7 months.

Personalizing neoadjuvant immune-checkpoint inhibition in patients with melanoma

Neoadjuvant immune-checkpoint inhibition is a promising emerging treatment approach for patients with surgically resectable macroscopic stage III melanoma. The neoadjuvant setting provides an ideal platform for personalized therapy owing to the very homogeneous nature of the patient population and the opportunity for pathological response assessments within several weeks of starting treatment, thereby facilitating the efficient identification of novel biomarkers. A pathological response to immune-checkpoint inhibitors has been shown to be a strong surrogate marker of both recurrence-free survival and overall survival, enabling timely analyses of the efficacy of novel therapies in patients with early stage disease. Patients with a major pathological response (defined as the presence of ≤10% viable tumour cells) have a very low risk of recurrence, which offers an opportunity to adjust the extent of surgery and any subsequent adjuvant therapy and follow-up monitoring. Conversely, patients who have only a partial pathological response or who do not respond to neoadjuvant therapy still might benefit from therapy escalation and/or class switch during adjuvant therapy. In this Review, we outline the concept of a fully personalized neoadjuvant treatment approach exemplified by the current developments in neoadjuvant therapy for patients with resectable melanoma, which could provide a template for the development of similar approaches for patients with other immune-responsive cancers in the near future.

Pathology of Immunotherapy-induced Responses in Cutaneous Melanoma: Current Evidences and Future Perspectives

Over the last years, immune checkpoint inhibitors (ICIs) have demonstrated remarkable anti-tumor activity and beneficial effects in patients with early and advanced melanoma. However, ICIs provide clinical benefit only in a minority of patients due to primary and/or acquired resistance mechanisms. Immunotherapy resistance is a complex phenomenon relying on genetic and epigenetic factors, which ultimately influence the interplay between cancer cells and the tumor microenvironment. Information is accumulating on the cellular and molecular mechanisms underlying the production of resistance and the resulting diminished therapeutic efficacy. In addition, current knowledge on predictors of response and toxicity to immunotherapy and on biomarkers that reliably identify resistant patients is in progress. In this review, we will focus on the tumor microenvironment changes induced by ICIs in melanoma, summarizing the available evidence of clinical trials in the neoadjuvant and metastatic setting. We will also overview the role of potential biomarkers in predicting disease response to ICIs, providing insight into current and future research in this field.

Neoadjuvant Checkpoint Immunotherapy and Melanoma: The Time Is Now

The role of neoadjuvant therapy is undergoing an historic shift in oncology. The emergence of potent immunostimulatory anticancer agents has transformed neoadjuvant therapy from a useful tool in minimizing surgical morbidity to a life-saving treatment with curative promise, led by research in the field of melanoma. Health practitioners have witnessed remarkable improvements in melanoma survival outcomes over the past decade, beginning with checkpoint immunotherapies and BRAF-targeted therapies in the advanced setting that were successfully adopted into the postsurgical adjuvant setting for high-risk resectable disease. Despite substantial reductions in postsurgical recurrence, high-risk resectable melanoma has remained a life-altering and potentially fatal disease. In recent years, data from preclinical models and early-phase clinical trials have pointed to the potential for greater clinical efficacy when checkpoint inhibitors are administered in the neoadjuvant rather than adjuvant setting. Early feasibility studies showed impressive pathologic response rates to neoadjuvant immunotherapy, which were associated with recurrence-free survival rates of over 90%. Recently, the randomized phase II SWOG S1801 trial (ClinicalTrials.gov identifier: NCT03698019) reported a 42% reduction in 2-year event-free survival risk with neoadjuvant versus adjuvant pembrolizumab in resectable stage IIIB-D/IV melanoma (72% v 49%; hazard ratio, 0.58; P = .004), establishing neoadjuvant single-agent immunotherapy as a new standard of care. A randomized phase III trial of neoadjuvant immunotherapy in resectable stage IIIB-D melanoma, NADINA (ClinicalTrials.gov identifier: NCT04949113), is ongoing, as are feasibility studies in high-risk stage II disease. With a swathe of clinical, quality-of-life, and economic benefits, neoadjuvant immunotherapy has the potential to redefine the contemporary management of resectable tumors.

Predictive value of radiological response, pathological response and relapse-free survival for overall survival in neoadjuvant immunotherapy trials: pooled analysis of 29 clinical trials

BACKGROUND

An increasing number of clinical trials are being conducted exploring the efficacy of neoadjuvant immune checkpoint inhibitors. Surrogate end-points for overall survival (OS) are urgently needed.

METHODS

Phase II or III trials of neoadjuvant immunotherapy that reported data on OS and surrogate end-points were identified from January 1, 2000, to November 25, 2022. Individual patient data, and trial-level data were requested from corresponding authors or extracted from eligible trials. At the individual level, correlations between radiological and pathological response and OS were measured by the Cox model and quantified by hazard ratio (HR). C-statistic was used to quantify the predictive performance of radiological and pathological response for OS. The coefficient of determination (R²) between RFS and OS was evaluated by a bivariate survival model.

RESULTS

A total of 29 trials reporting 2901 patients were included. ORR correlated with improved OS (3-year OS: 87.0% versus 70.4% for ORR versus non-ORR, respectively; HR, 0.34, 95% confidence interval [CI], 0.17-0.68). The HRs for OS in patients achieving MPR and pCR were 0.24 (95% CI, 0.12-0.46) and 0.13 (95% CI, 0.05-0.36). The survival benefit maintained after adjusting tumour type. C-statistics of ORR, MPR and pCR were 0.63, 0.63 and 0.65, respectively. The strength of association between RFS and OS was strong (R² = 0.88, 95% CI, 0.79-0.94).

CONCLUSIONS

These findings suggest that ORR, MPR, pCR and RFS are valid predictors for OS when using neoadjuvant immune checkpoint inhibitors. Moreover, MPR, pCR and RFS may be the most optimal surrogates for OS.

Neoadjuvant therapy for melanoma: A critical appraisal

The treatment of advanced melanoma has significantly changed since the development of targeted and immune therapy. To date, these agents have primarily been used in the adjuvant or metastatic setting. Given several theoretical advantages, there is increased interest in the use of these new therapeutics in the neoadjuvant setting. In this review, we detail the potential benefits and pitfalls of neoadjuvant therapy for melanoma, review the currently available data, and describe ongoing neoadjuvant trials.

Neoadjuvant immunotherapy across cancers: meeting report from the Immunotherapy Bridge-December 1st-2nd, 2021

After the success of immunotherapy in the treatment of advanced metastatic cancer, further evaluation in earlier settings, including high-risk, surgically-resectable disease is underway. Potential benefits of a neoadjuvant immunotherapeutic approach include presurgical tumor shrinkage, reduced surgical morbidity, early eradication of micrometastases and prevention of distant disease, and greater antigen-specific T cell response. For some cancers, pathologic response has been established as a surrogate measure for long-term outcomes, therefore offering the ability for early and objective assessment of treatment efficacy and the potential to inform and personalize adjuvant treatment clinical decision-making. Leveraging the neoadjuvant treatment setting offers the ability to deeply interrogate longitudinal tissue in order to gain translatable, pan-malignancy insights into response and mechanisms of resistance to immunotherapy. Neoadjuvant immunotherapy across cancers was a focus of discussion at the virtual Immunotherapy Bridge meeting (December 1-2, 2021). Clinical, biomarker, and pathologic insights from prostate, breast, colon, and non-small-cell lung cancers, melanoma and non-melanoma skin cancers were discussed and are summarized in this report.

Personalized response-directed surgery and adjuvant therapy after neoadjuvant ipilimumab and nivolumab in high-risk stage III melanoma: the PRADO trial

Neoadjuvant ipilimumab and nivolumab induces high pathologic response rates (pRRs) in clinical stage III nodal melanoma, and pathologic response is strongly associated with prolonged relapse-free survival (RFS). The PRADO extension cohort of the OpACIN-neo trial ( NCT02977052 ) addressed the feasibility and effect on clinical outcome of using pathologic response after neoadjuvant ipilimumab and nivolumab as a criterion for further treatment personalization. In total, 99 patients with clinical stage IIIb-d nodal melanoma were included and treated with 6 weeks of neoadjuvant ipilimumab 1 mg kg-1 and nivolumab 3 mg kg-1. In patients achieving major pathologic response (MPR, ≤10% viable tumor) in their index lymph node (ILN, the largest lymph node metastasis at baseline), therapeutic lymph node dissection (TLND) and adjuvant therapy were omitted. Patients with pathologic partial response (pPR; >10 to ≤50% viable tumor) underwent TLND only, whereas patients with pathologic non-response (pNR; >50% viable tumor) underwent TLND and adjuvant systemic therapy ± synchronous radiotherapy. Primary objectives were confirmation of pRR (ILN, at week 6) of the winner neoadjuvant combination scheme identified in OpACIN-neo; to investigate whether TLND can be safely omitted in patients achieving MPR; and to investigate whether RFS at 24 months can be improved for patients achieving pNR. ILN resection and ILN-response-tailored treatment were feasible. The pRR was 72%, including 61% MPR. Grade 3-4 toxicity within the first 12 weeks was observed in 22 (22%) patients. TLND was omitted in 59 of 60 patients with MPR, resulting in significantly lower surgical morbidity and better quality of life. The 24-month relapse-free survival and distant metastasis-free survival rates were 93% and 98% in patients with MPR, 64% and 64% in patients with pPR, and 71% and 76% in patients with pNR, respectively. These findings provide a strong rationale for randomized clinical trials testing response-directed treatment personalization after neoadjuvant ipilimumab and nivolumab.

Representativeness of the Index Lymph Node for Total Nodal Basin in Pathologic Response Assessment After Neoadjuvant Checkpoint Inhibitor Therapy in Patients With Stage III Melanoma

IMPORTANCE

Neoadjuvant checkpoint inhibition in patients with high-risk stage III melanoma shows high pathologic response rates associated with a durable relapse-free survival. Whether a therapeutic lymph node dissection (TLND) can be safely omitted when a major pathologic response in the largest lymph node metastasis at baseline (index lymph node; ILN) is obtained is currently being investigated. A previous small pilot study (n = 12) showed that the response in the ILN may be representative of the pathologic response in the entire TLND specimen.

OBJECTIVE

To assess the concordance of response between the ILN and the total lymph node bed in a larger clinical trial population.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective pathologic response analysis of a multicenter clinical trial population of patients from the randomized Study to Identify the Optimal Adjuvant Combination Scheme of Ipilimumab and Nivolumab in Melanoma Patients (OpACIN) and Optimal Neo-Adjuvant Combination Scheme of Ipilimumab and Nivolumab (OpACIN-neo) trials. Included patients were treated with 6 weeks neoadjuvant ipilimumab plus nivolumab. Patient inclusion into the trials was conducted from August 12, 2015, to October 24, 2016 (OpACIN), and November 24, 2016, and June 28, 2018 (OpACIN-neo). Data were analyzed from April 1, 2020, to August 31, 2021.

MAIN OUTCOMES AND MEASURES

Concordance of the pathologic response between the ILN and the TLND tumor bed. The pathologic response of the ILN was retrospectively assessed according to the International Neoadjuvant Melanoma Consortium criteria and compared with the pathologic response of the entire TLND specimen.

RESULTS

A total of 82 patients treated with neoadjuvant ipilimumab and nivolumab followed by TLND (48 [59%] were male; median age, 58.5 [range, 18-80] years) were included. The pathologic response in the ILN was concordant with the entire TLND specimen response in 81 of 82 patients (99%) and in 79 of 82 patients (96%) concordant when comparing the ILN response with the response in every individual lymph node. In the single patient with a discordant response, the ILN response (20% viable tumor, partial pathologic response) underestimated the entire TLND specimen response (5% viable, near-complete pathologic response). Two other patients each had 1 small nonindex node that contained 80% viable tumor (pathologic nonresponse) whereas all other lymph nodes (including the ILN) showed a partial pathologic response. In these 2 patients, the risk of regional relapse might potentially have been increased if TLND had been omitted.

CONCLUSIONS AND RELEVANCE

The results of this study suggest that the pathologic response of the ILN may be considered a reliable indicator of the entire TLND specimen response and may support the ILN response-directed omission of TLND in a prospective trial.

Neoadjuvant Immunotherapy: Leveraging the Immune System to Treat Early-Stage Disease

Given the success of immunotherapy in treating patients with metastatic disease in a variety of tumor types, there is tremendous enthusiasm for expanding the use of immunotherapy to those with early-stage cancer. Administering immunotherapy in the neoadjuvant, preoperative setting is a biologically sound approach because preclinical studies have shown that stronger and broader immune responses can be generated if immunotherapy is administered while the tumor and/or draining lymph nodes are intact. It is therefore likely that administering immunotherapy preoperatively will generate optimal immune responses, leading to high rates of pathologic response as well as improved long-term survival. Although neoadjuvant immunotherapy is currently only approved for use in combination with chemotherapy in triple-negative breast cancer and non-small cell lung cancer, it is anticipated that ongoing and future clinical trials will further define the role of neoadjuvant immunotherapy in many cancer types. These trials should be designed with appropriate survival endpoints and rigorous correlative studies to include imaging and biospecimen-based analyses to address currently unanswered questions that must be resolved to optimize the use of immunotherapy in early-stage disease.

A decade of checkpoint blockade immunotherapy in melanoma: understanding the molecular basis for immune sensitivity and resistance

Ten years since the immune checkpoint inhibitor ipilimumab was approved for advanced melanoma, it is time to reflect on the lessons learned regarding modulation of the immune system to treat cancer and on novel approaches to further extend the efficacy of current and emerging immunotherapies. Here, we review the studies that led to our current understanding of the melanoma immune microenvironment in humans and the mechanistic work supporting these observations. We discuss how this information is guiding more precise analyses of the mechanisms of action of immune checkpoint blockade and novel immunotherapeutic approaches. Lastly, we review emerging evidence supporting the negative impact of melanoma metabolic adaptation on anti-tumor immunity and discuss how to counteract such mechanisms for more successful use of immunotherapy.

Immune Checkpoint Therapy: Tumor Draining Lymph Nodes in the Spotlights

Tumor-draining lymph nodes play a paradoxical role in cancer. Surgeons often resect these sentinel lymph nodes to determine metastatic spread, thereby enabling prognosis and treatment. However, lymph nodes are vital organs for the orchestration of immune responses, due to the close encounters of dedicated immune cells. In view of the success of immunotherapy, the removal of tumor-draining lymph nodes needs to be re-evaluated and viewed in a different light. Recently, an important role for tumor-draining lymph nodes has been proposed in the immunotherapy of cancer. This new insight can change the use of immune checkpoint therapy, particularly with respect to the use in neoadjuvant settings in which lymph nodes are still operational.