Pediatric Colorectal Cancer: A Heterogenous Entity

Surgical management of rare tumors (Part 1)

With an annual cumulative occurrence of approximately 15,000 in North America, all childhood cancers are rare. Very rare cancers as defined by both the European Cooperative Study Group for Rare Pediatric Cancers and the Children's Oncology Group fall into two principal categories: those so uncommon (fewer than 2 cases/million) that their study is challenging even through cooperative group efforts (e.g., pleuropulmonary blastoma and desmoplastic small round cell tumor) and those that are far more common in adults and therefore rarely studied in children (e.g., thyroid, melanoma, and gastrointestinal stromal tumor). Treatment strategies for these latter tumors are typically based on adult guidelines, although the pediatric variants of these tumors may harbor different genetic signatures and demonstrate different behavior. If melanoma and differentiated thyroid cancer are excluded, other rare cancer types account for only 2% of the cancers in children aged 0 to 14. This article highlights several of the most common rare tumor types.

Understanding Diagnostic Costs Using Hospital-Based Encounters in the Year Before Diagnosis for Canadian Patients with Malignant Central Nervous System Tumours Compared to Common Cancers

Rare cancers pose significant diagnostic challenges, leading to more tests and higher healthcare expenditures (HEs). Understanding the financial implications of diagnosing rare cancers is crucial, particularly in Canada, where overall HEs are high (12% of the GDP in 2023). We investigated the pre-diagnostic hospital-based HE for patients with malignant central nervous system (CNS) tumours and compared it to patients with common cancers across Canadian provinces, using in-patient and ambulatory care data (2010-2014) from the Canadian Institute for Health Information. Pre-diagnostic HE was calculated as the change in total HE (in-patient and out-patient) during the 12 months before diagnosis, calculated as the HE within this period minus the average annual HE estimated over the two preceding years. Comparison groups included pediatric patients diagnosed with leukemia and patients aged over 15 diagnosed with colorectal cancer and lung cancer. We used quantile regression to estimate the adjusted effect of diagnosis with a CNS tumour on pre-diagnostic HE. The results indicated that HE for CNS patients was higher compared to those with common cancers. The top three factors contributing to HE variation were encounter type (in-patient/out-patient), province (Alberta/Ontario), and comorbidities (yes/no). Further investigation is warranted to understand the drivers of the cost differences.

Colorectal adenocarcinoma in children and adolescents

INTRODUCTION

Colorectal adenocarcinoma is rare in children and adolescents and tends to present with nonspecific signs and symptoms, leading to late diagnoses.

OBJECTIVES

Our aim was to describe the clinical presentation and progression in children and adolescents with colorectal adenocarcinoma treated at our hospital and detect possible predisposing conditions of this disease.

MATERIALS AND METHODS

Eight patients with colorectal adenocarcinoma were followed at the Hospital Posadas within the time frame of January 2000 and December 2021. We searched for diseases predisposing to this cancer.

RESULTS

The mean patient age was 16 years (between 11 and 17 years of age). Clinical presentation was abdominal pain in the 8 patients; 4 of them had pain in the right hypochondrium, 3 had abdominal tumor, 4 had rectal bleeding, and 3 had weight loss. Mean symptom duration was 9 weeks (range: 1-24 weeks). None of the patients showed predisposing illnesses. One patient presented with polyposis, with no cases in any other family member. Histology showed mucinous adenocarcinoma in all the patients, 4 of whom had the signet ring cell subtype. The primary tumor was located in the right colon in 6 patients. At diagnosis, staging according to the modified Dukes classification was: I: one patient; IIb: one patient; IIIb: one patient; IIIc: one patient; and IV: 4 patients. All patients except 2 received chemotherapy and one patient received radiotherapy. Overall survival at 3 years was 25%.

CONCLUSIONS

All patients presented with mucinous adenocarcinoma, no predisposing diseases were found, and the children with colorectal cancer had a very poor prognosis. Colorectal cancer diagnosis should be considered in children presenting with acute abdominal pain, abdominal tumor, or lower gastrointestinal bleeding, especially if there is weight loss.

NCCN Guideline Concordance Improves Survival in Pediatric and Young Adult Rectal Cancer

BACKGROUND

Although management guidelines in adult rectal cancer are widely studied, no consensus guidelines exist for the management of pediatric and young adult rectal cancer.

METHODS

The National Cancer Database (2004-2018) was queried for pediatric (age 0-21) and young adult (age 22-40) patients with rectal cancer. Patients were analyzed for receipt of National Comprehensive Cancer Network (NCCN) guideline-concordant therapy. Impact on survival was evaluated using Cox regression and Kaplan-Meier analysis.

RESULTS

6655 patients (108 pediatric and 6547 young adult patients) with rectal cancer were included. Similar to previously published NCCN quality measures with overall guideline concordance approaching 90 % in adults, 89.6 % of pediatric and 84.6 % of young adult patients were classified as receiving pre-operative guideline-concordant therapy. However, pediatric patients were significantly less likely to receive post-operative guideline-concordant therapy than young adult patients (65.3 % verse 76.7 %, respectively, p = 0.008). Risk of death was significantly lower for pediatric patients who received post-operative guideline-concordant therapy (HR, 0.313; CI, 0.168-0.581; p < 0.001). In young adult patients, risk of death was significantly lower for those who received pre-operative guideline-concordant therapy (HR, 0.376, CI 0.338-0.417, p < 0.001), and post-operative guideline-concordant therapy (HR, 0.456; CI 0.413-0.505; p < 0.001).

DISCUSSION

NCCN-based guidelines may reasonably guide peri-operative management decisions and improve survival in pediatric and young adult rectal cancer. Given the rarity of this cancer in young patients, employment of an experienced surgical and oncologic multidisciplinary team, along with discussion and involvement of the patient and family, are keys for balancing risks and benefits to offering the best therapeutic strategy.

TYPE OF STUDY

Retrospective.

LEVEL OF EVIDENCE

Level III.

Pathological complete response after neoadjuvant immunotherapy combined with chemotherapy in pediatric rectal carcinoma: A case report

Background

Pediatric colorectal carcinoma (PCRC) is a rare non-embryonal tumor with an incidence of 0.1% to 1% of adults. Immune checkpoint inhibitors (ICIs) targeting programmed death-1 (PD-1) have shown significant efficacy in defective mismatch repair/Microsatellite instability-high (dMMR/MSI-H) metastatic CRC (mCRC). Although several studies have reported neoadjuvant immunotherapy (NIT) in MSI-H/dMMR non-mCRC patients, not all patients achieved pathological complete remission (pCR). There are differences between PCRC and adult colorectal carcinoma (CRC), and the role of NIT in PCRC remains to be further defined.

Case presentation

We report the case of a 12-year-old child who was admitted to the hospital with abdominal pain and vomiting for more than 3 months. The child's diagnosis was difficult and complex. He was initially diagnosed with intestinal obstruction, eventually diagnosed with a rare PCRC and identified as locally advanced colorectal cancer (LACRC) with genetic sequencing results showing MSI-H. After a thorough evaluation by clinicians, he received 4 cycles of Camrelizumab (anti-PD-1 antibody) + CapeOx (capecitabine and oxaliplatin) NIT combination chemotherapy. Repeat imaging and all tumor markers were unremarkable, and R0 resection was achieved. Postoperative pathology showed a tumor regression grade (TRG) of 0 grade determined as pCR. Postoperative review has not shown any recurrence or metastasis to date and the prognosis is good.

Conclusion

PCRC should improve the diagnostic efficiency to prevent misdiagnosis and miss the best time for treatment. NIT and or chemotherapy can be a reasonable and effective treatment option for dMMR/MSI-H locally advanced PCRC. Our report provides some support and evidence for neoadjuvant immunotherapy for locally advanced PCRC, while highlighting the importance of preoperative detection of microsatellite status for locally advanced PCRC.

Routine Immunohistochemical Analysis of Mismatch Repair Proteins in Colorectal Cancer—A Prospective Analysis

Simple Summary

Recognition of a hereditary colorectal cancer (CRC) syndrome is crucial. Our aim was to assess the value of routine immunohistochemistry screening for mismatch repair proteins deficiency in CRC patients under 70 years-old. In our cohort, this inclusive strategy allowed the identification of Lynch Syndrome patients that could otherwise be missed using a restrictive approach that relies only on Amsterdam and Bethesda criteria. This study strengthens current recommendations and highlights the role of universal CRC screening for MMR protein status.

Abstract

Recognition of a hereditary colorectal cancer (CRC) syndrome is crucial and Lynch Syndrome (LS) is the most frequent immunohistochemistry (IHC)—screening for mismatch repair proteins (MMR) deficiency in CRC is therefore advocated. An unicentric cohort study was conducted in a central Oncological Hospital to assess its results. All patients under 70 years-old admitted between July 2017–June 2019 and submitted to surgery for CRC were included. Of 275 patients, 56.0% were male, median age 61.0 (IQR:54.5–65.0), with synchronous tumors in six. Histology revealed high grade adenocarcinoma in 8.4%; mucinous and/or signet ring differentiation in 11.3%; and lymphocytic infiltration in 29.8%. Amsterdam (AC) and Bethesda (BC) Criteria were fulfilled in 11 and 74 patients, respectively. IHC revealed loss of expression of MMR proteins in 24 (8.7%), mostly MLH1 and PMS2 (n = 15) and PMS2 (n = 4). Among these, no patients fulfilled AC and 13 fulfilled BC. BRAF mutation or MLH1 promoter hypermethylation was found in four patients with MLH1 loss of expression. Genetic diagnosis was performed in 51 patients, 11 of them with altered IHC. LS was diagnosed in four, and BC was present in three. One patient would not have been diagnosed without routine IHC screening. These results strengthen the important role of IHC screening for MMR proteins loss of expression in CRC.