Efficacy of immunotherapy in mismatch repair-deficient advanced colorectal cancer in routine clinical practice. An AGEO study

BACKGROUND

Immunotherapy demonstrated remarkable efficacy in metastatic colorectal cancers (mCRCs) with mismatch repair deficiency (MMRd)/microsatellite instability (MSI). However, data regarding efficacy and safety of immunotherapy in the routine clinical practice are scarce.

PATIENTS AND METHODS

This is a retrospective, multicenter study aiming to evaluate efficacy and safety of immunotherapy in routine clinical practice and to identify predictive markers for long-term benefit. Long-term benefit was defined as progression-free survival (PFS) exceeding 24 months. All patients who received immunotherapy for an MMRd/MSI mCRC were included. Patients who received immunotherapy in combination with another known effective therapeutic class agent (chemotherapy or tailored therapy) were excluded.

RESULTS

Overall, 284 patients across 19 tertiary cancer centers were included. After a median follow-up of 26.8 months, the median overall survival (mOS) was 65.4 months [95% confidence interval (CI) 53.8 months-not reached (NR)] and the median PFS (mPFS) was 37.9 months (95% CI 30.9 months-NR). There was no difference in terms of efficacy or toxicity between patients treated in the real-world or as part of a clinical trial. Overall, 46.6% of patients had long-term benefit. Independent markers associated with long-term benefit were Eastern Cooperative Oncology Group-performance status (ECOG-PS) 0 (P = 0.025) and absence of peritoneal metastases (P = 0.009).

CONCLUSIONS

Our study confirms the efficacy and safety of immunotherapy in patients with advanced MMRd/MSI CRC in the routine clinical practice. ECOG-PS score and absence of peritoneal metastases provide simple markers that could help identify patients who benefit the most from this treatment.

Abstract CT530: Multiorgan metabolic imaging response assessment of abemaciclib (MiMe-A): Oncodistinct 002

Background: Abemaciclib (A) activity against breast cancer as monotherapy or combined with endocrine therapy warrants further investigations in other cancer types. However, its significant toxicity profile illustrates the challenge of defining more precisely the patients unlikely to benefit from it, sparing them from useless toxicities. FDG-PET/CT can identify treatment-refractory disease with high negative predictive value, soon after the treatment onset and before morphological changes are observed. MiMe-A was built on the assumption that a therapy that does not induce tumoral metabolic changes 14 days after its onset is unlikely to achieve a significant clinical benefit.

Methods: A multicenter phase II basket trial assessed the efficacy of A in 5 cancers types (cholangiocarcinoma, endometrial, urothelial carcinomas, oesophagal adeno- and squamous cell carcinomas). The primary endpoint is the ‘treatment success’, defined as metabolic response according to PERCIST at FDG-PET/CT performed during the first cycle (D14) and absence of disease progression per RECIST 1.1 after two cycles of A. A Simon’s 2-stage design was used in each cohort based on the null hypothesis that the treatment success rate will be ≤20%. An interim analysis for futility was performed on each cohort after accrual of 17 patients during the first stage.

Results: The baseline characteristics and the metabolic and morphologic evaluation of eligible patients are shown below.

*: stop treatment before the two months (due to progression or toxicities) IQR: interquartile range, PR: partial response, SD: stable disease, PD: progressive disease

The treatment success rate was 0% for each cancer type except for urothelial carcinoma (5,9% (1/17 treatment success). Toxicities were mainly graded 1 or 2, including diarrhea, nausea, fatigue and haematological.

Conclusion: A did not show significant anti-tumour activity in any of the five cohorts. But early metabolic response was noted in 29% of the oesophageal squamous cell carcinoma population, this finding did not translate in disease control at two months. This could be explained by an initial response rapidly followed by tumoral escape. A combination of A with other drugs should be explored in this cancer type.

Esophageal adenocarcinomaN=17 Esophageal Squamous cell carcinomaN=17 CholangiocarcinomaN=17 Endometrial carcinomaN=17 Urothelial CarcinomaN=17 Baselinecharacteristics Age range 36-83 56-77 50-85 57-84 46-80 Median age (IQR) 65 (55-68) 67 (63-71) 70 (67-74) 68(64-73) 67 (63-71) Median number of lines of prior treatments (IQR) 3 (2-4) 3 (2-4) 2 (1-2) 3 (2-3) 3 (2-3) Metabolic response (PERCIST) assessment Complete metabolic response 0/17 0/17 0/17 0/17 0/17 Partial metabolic response 2/17 5/17 1/17 0/17 2/17 Stable metabolic disease 8/17 4/17 5/17 8/17 7/17 Progressive metabolic disease 4/17 7/17 9/17 6/17 4/17 Not evaluable 3/17 1/17 2/17 3/17 4/17 % Complete or partial metabolic response (95% CI) 12% (2%-36%) 29% (10%-56%) 6% (0%-29%) 0% (0%-20%) 12% (1%-36%) Response by RECIST (after 2 cycles) PR 1/17 1/17 0/17 0/17 0/17 SD 3/17 2/17 5/17 5/17 8/17 PD 6/17 10/17 7/17 9/17 8/17 Not available* 7/17 4/17 5/17 3/17 1/17

Citation Format: Laura Polastro, Nuria Kotecki, Diogo Martins-Branco, Diane Delaroche, Philippe Barthelemy, Stephane Holbrechts, Philippe Vergauwe, JC Goemine, Gauthier Demolin, Hans Prenen, Florian Clatot, Carlos Gomez Roca, Paulus Kristanto, Marianne Peasmans, Ahmad Awada, Alain hendlisz, Aurélien Carnot, Fransceco Sclafani, Philippe Aftimos. Multiorgan metabolic imaging response assessment of abemaciclib (MiMe-A): Oncodistinct 002 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT530.

ESMO Congress 2021: highlights from the EORTC gastrointestinal tract cancer group's perspective

There has been no major change of practice in gastrointestinal oncology at the European Society for Medical Oncology (ESMO) symposium 2021, but confirmation that immunotherapy in combination with chemotherapy has become standard of care in several indications. The European Organisation for Research and Treatment of Cancer (EORTC) Gastrointestinal Track Cancer Group has selected important phase II and III trials presented during the symposium across all gastrointestinal cancers as well as early reports on new drugs or new combinations that may change practice in the future.

Grey areas and evidence gaps in the management of rectal cancer as revealed by comparing recommendations from clinical guidelines

BACKGROUND

While the management of nonmetastatic and oligometastatic rectal cancer has rapidly evolved over the last few decades, many grey areas and highly debated topics remain that foster significant variation in clinical practice. We aimed to identify controversial points and evidence gaps in this disease setting by systematically comparing recommendations from national and international clinical guidelines.

METHODS

Twenty-six clinical questions reflecting practical challenges in the routine management of nonmetastatic and oligometastatic rectal cancer patients were selected. Recommendations from the ESMO, NCCN, JSCCR, Australian and Ontario guidelines were extrapolated and compared using a 4-tier classification system (i.e., identical/very similar, similar, slightly different, different). Overall agreement between guidelines (i.e., substantial/complete disagreement, partial disagreement, partial agreement, substantial/complete agreement) was assessed for each clinical question and compared against the highest level of available evidence by using the χ² statistic test.

RESULTS

Guidelines were in substantial/complete agreement, partial agreement, partial disagreement, and substantial/complete disagreement for 8 (30.8%), 2 (7.7%), 7 (26.9%), and 9 (34.6%) clinical questions, respectively. High level of evidence supported clinical recommendations in 3/10 cases (30%) where guidelines were in agreement and in 10/16 cases (62.5%) where guidelines were in disagreement (χ² = 2.6, p = 0.106). Agreement was frequently reached for questions regarding diagnosis, staging, and radiology/pathology pro-forma reporting, while disagreement characterised most of the treatment-related topics.

CONCLUSIONS

Substantial variation exists across clinical guidelines in the recommendations for the management of nonmetastatic and oligometastatic rectal cancer. This variation is only partly explained by the lack of supporting, high-level evidence.

Session 2: Are we ready for primary chemotherapy in rectal cancer: who, when, why?

The potential of preoperative chemotherapy in rectal cancer is the subject of investigation in a number of global randomized trials. In this overview and expert discussion, Professor Cervantes summarizes the findings of numerous Phase II trials testing neoadjuvant chemotherapy. The crucial points in the next phase of trials include: patient selection, whether radiotherapy can be omitted altogether and whether chemotherapy can be used to augment the initial response to chemoradiotherapy. Finally, with the emergence of Magnetic Resonance Tumour Regression Grade a reliable method for assessing response after initial chemoradiotherapy, we ask if this can be used to drive the use of further selective chemotherapy to augment response.

Microsatellite instability is associated with reduced disease specific survival in stage III colon cancer

BACKGROUND

Up to 15% of colorectal cancers exhibit microsatellite instability (MSI), where errors in replication go unchecked due to defects in the mismatch repair system. This study aimed to determine survival in a large single-centre series of 1250 consecutive colorectal cancers subjected to universal MSI testing.

METHODS

Clinical and pathological features of patients with colorectal cancer identified on prospectively maintained colorectal and pathology databases at St. Vincent's University Hospital from 2004 to May 2012 were examined. Mismatch repair (MMR) status was determined by immunohistochemistry. Kaplan-Meier curves, the log-rank test and Cox regression were used to associate survival with clinical and pathological characteristics.

RESULTS

Of the 1250 colorectal cancers in the study period, 11% exhibited MSI (n = 138). Patients with MSI tumours had significantly lower rates of lymph node and distant metastases (MSI N+ rate: 24.8% compared with MSS N+ rate: 46.2%, p < 0.001). For Stage I and II disease MSI was associated with improved disease free survival (DSS) compared with MSS colon cancer. However, patients with Stage III MSI colon cancers had a worse DSS than those with MSS tumours. Stage III MSI tumours exhibited higher rates of lymphovascular invasion and perineural invasion than Stage I/II MSI tumours.

CONCLUSION

MSI is associated with a reduced risk of nodal and distant metastases, with an improved DSS in Stage I/II colon cancer. However, when MSI tumours progress to Stage III these patients had worse outcomes and pathological features. New strategies for this cohort of patients may be required to improve outcomes.

PAN-EX: a pooled analysis of two trials of neoadjuvant chemotherapy followed by chemoradiotherapy in MRI-defined, locally advanced rectal cancer

BACKGROUND

EXPERT and EXPERT-C were phase II clinical trials of neoadjuvant chemotherapy (NACT) followed by chemoradiotherapy (CRT) in high-risk, locally advanced rectal cancer (LARC).

DESIGN

We pooled individual patient data from these trials. The primary objective was overall survival (OS) in the intention-to-treat (ITT) population. Prognostic factors were also analysed.

RESULTS

A total of 269 patients were included. Of these, 91.1% completed NACT, 88.1% completed CRT and 240 (89.2%) underwent curative surgery (R0/R1). After a median follow-up of 71.9 months, 5-year progression-free survival (PFS) and OS were 66.4% and 73.3%, respectively. In the group of R0/R1 resection patients, 5-year relapse-free survival (RFS) and OS were 71.6% and 77.2%, respectively, with local recurrence occurring in 5.5% and distant metastases in 20.6% of cases. Significant prognostic factors after multivariate analyses included age, tumour grade and MRI extramural venous invasion (mrEMVI) at baseline, MRI tumour regression grade (mrTRG) after CRT, ypT stage after surgery and adherence to study treatment. mrTRG after NACT was associated with PFS (P = 0.002) and OS (P = 0.018) and appeared to stratify patients based on the incremental benefit from sequential CRT. Among the outcome measures considered, in the subgroup of R0/R1 resection patients, ypT and ypStage had the highest predictive accuracy for RFS (concordance index: 0.6238 and 0.6252, respectively) and OS (concordance index: 0.6094 and 0.6132, respectively).

CONCLUSIONS

Administering NACT before CRT could be a potential strategy for high-risk LARC. In this setting, mrTRG after CRT is an independent prognostic factor, while mrTRG after NACT should be tested as a parameter for treatment selection in trials of NACT ± CRT. ypT stage may be a valuable surrogate end point for future phase II trials investigating intensified neoadjuvant treatments in similar patient populations.

Prognostic role of the LCS6 KRAS variant in locally advanced rectal cancer: results of the EXPERT-C trial

BACKGROUND

Lethal-7 (let-7) is a tumour suppressor miRNA which acts by down-regulating several oncogenes including KRAS. A single-nucleotide polymorphism (rs61764370, T > G base substitution) in the let-7 complementary site 6 (LCS-6) of KRAS mRNA has been shown to predict prognosis in early-stage colorectal cancer (CRC) and benefit from anti-epidermal growth factor receptor monoclonal antibodies in metastatic CRC.

PATIENTS AND METHODS

We analysed rs61764370 in EXPERT-C, a randomised phase II trial of neoadjuvant CAPOX followed by chemoradiotherapy, surgery and adjuvant CAPOX plus or minus cetuximab in locally advanced rectal cancer. DNA was isolated from formalin-fixed paraffin-embedded tumour tissue and genotyped using a PCR-based commercially available assay. Kaplan-Meier method and Cox regression analysis were used to calculate survival estimates and compare treatment arms.

RESULTS

A total of 155/164 (94.5%) patients were successfully analysed, of whom 123 (79.4%) and 32 (20.6%) had the LCS-6 TT and LCS-6 TG genotype, respectively. Carriers of the G allele were found to have a statistically significantly higher rate of complete response (CR) after neoadjuvant therapy (28.1% versus 10.6%; P = 0.020) and a trend for better 5-year progression-free survival (PFS) [77.4% versus 64.5%: hazard ratio (HR) 0.56; P = 0.152] and overall survival (OS) rates (80.3% versus 71.9%: HR 0.59; P = 0.234). Both CR and survival outcomes were independent of the use of cetuximab. The negative prognostic effect associated with KRAS mutation appeared to be stronger in patients with the LCS-6 TT genotype (HR PFS 1.70, P = 0.078; HR OS 1.79, P = 0.082) compared with those with the LCS-6 TG genotype (HR PFS 1.33, P = 0.713; HR OS 1.01, P = 0.995).

CONCLUSION

This analysis suggests that rs61764370 may be a biomarker of response to neoadjuvant treatment and an indicator of favourable outcome in locally advanced rectal cancer possibly by mitigating the poor prognosis of KRAS mutation. In this setting, however, this polymorphism does not appear to predict cetuximab benefit.

RAS mutations and cetuximab in locally advanced rectal cancer: results of the EXPERT-C trial

BACKGROUND

RAS mutations predict resistance to anti-epidermal growthfactor receptor (EGFR) monoclonal antibodies in metastatic colorectal cancer. We analysed RAS mutations in 30 non-metastatic rectal cancer patients treated with or without cetuximab within the 31 EXPERT-C trial.

METHODS

Ninety of 149 patients with tumours available for analysis were KRAS/BRAF wild-type, and randomly assigned to capecitabine plus oxaliplatin (CAPOX) followed by chemoradiotherapy, surgery and adjuvant CAPOX or the same regimen plus cetuximab (CAPOX-C). Of these, four had a mutation of NRAS exon 3, and 84 were retrospectively analysed for additional KRAS (exon 4) and NRAS (exons 2/4) mutations by using bi-directional Sanger sequencing. The effect of cetuximab on study end-points in the RAS wild-type population was analysed.

RESULTS

Eleven (13%) of 84 patients initially classified as KRAS/BRAF wild-type were found to have a mutation in KRAS exon 4 (11%) or NRAS exons 2/4 (2%). Overall, 78/149 (52%) assessable patients were RAS wild-type (CAPOX, n=40; CAPOX-C, n=38). In this population, after a median follow-up of 63.8months, in line with the initial analysis, the addition of cetuximab was associated with numerically higher, but not statistically significant, rates of complete response (15.8% versus 7.5%, p=0.31), 5-year progression-free survival (75.5% versus 67.5%, hazard ratio (HR) 0.61, p=0.25) and 5-year overall survival (83.8% versus 70%, HR 0.54, p=0.20).

CONCLUSIONS

RAS mutations beyond KRAS exon 2 and 3 were identified in 17% of locally advanced rectal cancer patients. Given the small sample size, no definitive conclusions on the effect of additional RAS mutations on cetuximab treatment in this setting can be drawn and further investigation of RAS in larger studies is warranted.

HER2 in high-risk rectal cancer patients treated in EXPERT-C, a randomized phase II trial of neoadjuvant capecitabine and oxaliplatin (CAPOX) and chemoradiotherapy (CRT) with or without cetuximab

BACKGROUND

HER2 is an established therapeutic target in breast and gastric cancers. The role of HER2 in rectal cancer is unclear, as conflicting data on the prevalence of HER2 expression in this disease have been reported. We evaluated the prevalence of HER2 and its impact on the outcome of high-risk rectal cancer patients treated with neoadjuvant CAPOX and CRT±cetuximab in the EXPERT-C trial.

PATIENTS AND METHODS

Eligible patients with available tumour tissue for HER2 analysis were included. HER2 expression was determined by immunohistochemistry (IHC) in pre-treatment biopsies and/or surgical specimens (score 0-3+). Immunostaining was scored according to the consensus panel recommendations on HER2 scoring for gastric cancer. Tumours with equivocal IHC result (2+) were tested for HER2 amplification by D-ISH. Tumours with IHC 3+ or D-ISH ratio ≥2.0 were classified as HER2+. The impact of HER2 on primary and secondary end points of the study was analysed.

RESULTS

Of 164 eligible study patients, 104 (63%) biopsy and 114 (69%) surgical specimens were available for analysis. Only 3 of 104 (2.9%) and 3 of 114 (2.6%) were HER2+, respectively. In 77 patients with paired specimens, concordance for HER2 status was found in 74 (96%). Overall, 141 patients were assessable for HER2 and 6 out of 141 (4.3%) had HER2 overexpression and/or amplification. The median follow-up was 58.6 months. HER2 was not associated with a difference in the outcome for any of the study end points, including in the subset of 90 KRAS/BRAF wild-type patients treated±cetuximab.

CONCLUSIONS

Based on the low prevalence of expression as recorded in the EXPERT-C trial, HER2 does not appear to represent a useful therapeutic target in high-risk rectal cancer. However, the role of HER2 as a potential predictive biomarker of resistance to anti-EGFR-based treatments and a therapeutic target in anti-EGFR refractory metastatic colorectal cancer (CRC) warrants further investigation.

TRIAL REGISTRATION

ISRCTN Register: 99828560.

Response assessment in oncology: limitations of anatomic response criteria in the era of tailored treatments

Evaluation of tumor response is a vital element in clinical oncology research, particularly in the development of new drugs. Tumor response also plays a significant role in treatment decisions made by clinicians in practice. The underlying concept of tumor response, however, was developed as a result of limited understanding of tumor biology coupled with restricted availability of both effective treatments and imaging modalities. In recent years, impressive advances have been made in the treatment of cancer. Groundbreaking advances in our understanding of the molecular biology of tumor growth and proliferation have been made. New biologic agents have been approved for the treatment of several malignancies and, in many cases, biomarkers have been identified that can help predict those patients who will benefit. Pre-operative chemotherapy is now established for a number of tumor types. Modern imaging technologies allowing functional characterization of tumors have been introduced into clinical practice. In this new therapeutic landscape, the existing concept of tumor response risks becoming an anachronism, and revision of the criteria used to define tumor response is warranted. In this paper, we critically review the limitations of the classic criteria for tumor response assessment, and briefly discuss the potential role of alternative methodologies in providing a new, functional definition of tumor response.

Phase II study of NGR-hTNF, a selective vascular targeting agent (VTA), administered as single agent in patients (pts) with colorectal cancer (CRC) refractory to standard regimens

4088

Background: NGR-hTNF is a VTA exploiting a tumor-homing peptide (NGR) that selectively binds to an aminopeptidase N/CD13 overexpressed by tumor blood vessels. In preclinical models, NGR-hTNF showed antitumor activity both at low and at high doses. Methods: Pts with CRC resistant/refractory to standard treatments, including biological agents, were treated with low-dose NGR-hTNF given intravenously at 0.8 μg/m2 as 1-hour infusion every 3 weeks (q3w). This phase II trial had a 2-stage design with 16 and 27 pts to be enrolled after first and second stage, respectively. Progression-free survival (PFS) was the primary end-point with reassessment performed q6w. Results: From January to May 2007, 33 pts with radiologically- documented progressive disease after last therapy were evaluated over 111 cycles (range, 1–10). Pts characteristics were: median age: 65 years (range, 53 to 79); M/F 16/17; PS 0/1 26/7. Median number of prior regimens was 3 (range, 2 to 5). Eight pts (25%) were pre-treated with ≥4 lines and 22 (67%) with biological agents. Neither grade 3–4 treatment-related adverse events nor toxicity-related deaths were observed. Main grade 1–2 toxicities per patient were infusion-related chills (47%) and transient blood pressure increase (9%). One partial response (3%) lasting 5 months and 12 stable diseases (36%) were reported. Median PFS was 2.5 months (95% CI, 2.2–2.8). In a post-hoc analysis, no differences in PFS were detected according to baseline characteristics. With a median follow-up time of 18.4 months (95% CI, 18.3–18.5), 11 pts (33%) were still alive. Median overall survival (OS) was 13.1 months and the 2-year OS rate was 22%. In the subset of stable or responder pts, the median PFS and OS were 3.8 months and 15.4 months, respectively. The 6-month PFS rate in the prior-biological and biological-naïve cohorts was 5% and 20%, respectively, whereas 1-year OS rate was 41% and 72%, respectively. Conclusions: Based on the favorable toxicity profile and disease control in heavily pre-treated CRC patients, NGR-hTNF will be further developed in combination with standard chemotherapy.

[Table: see text]

[Penal treatment and rehabilitation of the convict in the new Penal Code of San Marino. Juridical and criminological aspects]

The Republic of San Marino adopted a new Penal Code which came into force on Ist January 1975; it replaced the former one of 15th Sept. 1865. After having stated the typical aspects of the Penal Procedure System therein enforceable, the Authors examine the rules concerning criminal responsibility and the danger of committing new crimes. They point out and criticize the relevant contradictions. In explaining the measures regarding punishment and educational rehabilitation provided for by the San Marino's legal system, the Authors later consider them from a juridical and criminological viewpoint. If some reforms must be approved (for example: biopsychical inquiry on the charged person, probation, week-end imprisonments, fines according to the incomes of the condemned, etc.). the Authors stress that some legal provisions may appear useless and unrealistic when one considers the environmental conditions of the little Republic. The Authors conclude that Penal Procedure Law is not in accordance with Penal Law and, consequently, they hope that a new reform will be grounded on the needs arising from the crimes perpetrated in loco. It shall be, however, necessary to plan a co-ordination among the two Codes within a framework of de-criminalization of many acts which are now punishable as crime.

[Alternative imporisonment measures in the penal legislation of the Socialist Republic of Poland]

On April 19th, 1969 the People's Poland Parliament adopted a new penal legislation consisting of a Penal Code, a Code of Criminal Procedure and an executory Penal Code, which all came into force January 1st, 1970. The distinctive peculiarity of the above mentioned Codes, as the Authors have pointed out, is that they conform to the recent political, social and economic democratization of Poland and to the structure and dynamics of delinquency in this country. In examining the measures concerning educational rehabilitation provided for by the penal law in question, the Authors have started discussing questions like restriction on personal freedom, conditional suspension of criminal procedings, supervision of the convict who has been given the benefice of conditional suspension of the execution of sentence or of conditional release and supervision of the recidivist as well as points related to warranty and postjail care. Though these measures show some similarity to those provided for by bourgeois penal legislations, they result from a quite anthithetic ideology according to which punishment has to perform a double function of defence of working-class achievements as well as of an effective rehabilitation of the convict. A detailed analysis of the theoretical premises and of the actual carrying out of these measures shows, the Authors say, that though they represent only a further stage in the development of socio-juridical progress, they are put in conformity with the criminal policy's trends and the politico-ideological contents of a socialist government. They testify therefore an actual effort to make social rehabilitation of the convict possible in that they prevent the exertion of all negative psycho-pathogenic influences of jail environment on the convict, especially in case of slight crimes. The ultimate importance of these measures is that they can be considered an articulate attempt to promote actual social rehabilitation of the convict and therefore they are a real contribution in the resolution of delinquency which is viewed in Poland, where a process of socio-political trnasformation has been recently taking place, as part of the heritage from the past bourgeois government.