Colonic adenomatous polyposis syndromes: clinical management

Incidental cancer in colectomy specimens from patients with familial adenomatous polyposis: single centre experience and literature review

BACKGROUND

Since cancer development is inevitable in patients with familial adenomatous polyposis (FAP), we aimed to determine the incidence of incidental malignancy in prophylactic colectomy specimens.

METHODS

The files of patients who underwent prophylactic surgery for FAP between 2010 and 2020 were retrospectively reviewed. The incidence of incidental malignancy in histopathological specimens was examined and a comprehensive literature review was made.

RESULTS

Fifty-five patients were included in the study, of whom 30 patients had a diagnosis of primary malignancy. Prophylactic colectomy was performed on 25 patients. The pathology results indicated that the specimens were benign in 12 patients (48%) and revealed carcinoma in situ in 11 patients (44%). Incidental malignancy was detected in 2 patients (8%). In the literature review, there were 243 patients who underwent prophylactic colectomy and incidental cancer was detected in 25 patients (10.3%) with the stages of 1 (7.4%), 2 (2.1%), and 3 (0.8%), respectively.

CONCLUSIONS

Incidental cancer is not rare in patients who have undergone prophylactic colectomy for FAP. Hopefully. they are usually at early stages and unexpected advanced cancers are seen rarely.

Prevalence and Management of Cancer of the Rectal Stump after Total Colectomy and Rectal Sparing in Patients with Familial Polyposis: Results from a Registry-Based Study

BACKGROUND

The balance between quality of life and colorectal cancer risk in familial adenomatous polyposis (FAP) patients is of primary importance. A cut-off of less than 30 polyps under 1 cm of diameter in the rectum has been used as an indication for performing ileo-rectal anastomosis (IRA) in terms of lower rectal cancer risk. This study aimed to assess clinical and surgical features of FAP patients who developed cancer of the rectal stump.

METHODS

This retrospective study included all FAP patients who underwent total colectomy/IRA from 1977 to 2021 and developed subsequent rectal cancer. Patients' features were reported using descriptive statistics by considering the overall case series and within pre-specified classes of age (<20, 20-30, and >30 years) at first surgery.

RESULTS

Among the 715 FAP patients, 47 (6.57%, 95% confidence interval: 4.87; 8.65) developed cancer in the rectal stump during follow-up. In total, 57.45% of the population were male and 38.30% were proband. The median interval between surgery and the occurrence of rectal cancer was 13 years. This interval was wider in the youngest group (p-value: 0.012) than the oldest ones. Twelve patients (25.53%) received an endoscopic or minimally invasive resection. Amongst them, 61.70% were Dukes stage A cancers.

CONCLUSIONS

There is a definite risk of rectal cancer after total colectomy/IRA; however, the time interval from the index procedure to cancer developing is long. Minimally invasive and endoscopic treatments should be the procedures of choice in patients with early stage cancers.

Ileal-anal pouches: A review of its history, indications, and complications

The ileal pouch anal anastomosis (IPAA) has revolutionised the surgical management of ulcerative colitis (UC) and familial adenomatous polyposis (FAP). Despite refinement in surgical technique(s) and patient selection, IPAA can be associated with significant morbidity. As the IPAA celebrated its 40^th anniversary in 2018, this review provides a timely outline of its history, indications, and complications. IPAA has undergone significant modification since 1978. For both UC and FAP, IPAA surgery aims to definitively cure disease and prevent malignant degeneration, while providing adequate continence and avoiding a permanent stoma. The majority of patients experience long-term success, but “early” and “late” complications are recognised. Pelvic sepsis is a common early complication with far-reaching consequences of long-term pouch dysfunction, but prompt intervention (either radiological or surgical) reduces the risk of pouch failure. Even in the absence of sepsis, pouch dysfunction is a long-term complication that may have a myriad of causes. Pouchitis is a common cause that remains incompletely understood and difficult to manage at times. 10% of patients succumb to the diagnosis of pouch failure, which is traditionally associated with the need for pouch excision. This review provides a timely outline of the history, indications, and complications associated with IPAA. Patient selection remains key, and contraindications exist for this surgery. A structured management plan is vital to the successful management of complications following pouch surgery.

Aggressive mutation in a familial adenomatous polyposis syndrome family: when phenotype guides clinical surveillance

Familial adenomatous polyposis (FAP) is an autosomal dominant genetic condition, caused by mutations in the adenomatous polyposis coli (APC) tumor suppressor gene. Desmoid tumors (DTs) are seen in 15% to 20% of FAP patients. Specific location of mutation serves as a guide to predict colonic and extra colonic manifestations and their aggressiveness. A severe FAP-phenotypic family was registered in a genetic counselling high-risk Uruguayan hereditary cancer clinic. Proband's DNA was analysed by NGS, detecting a pathogenic mutation in APC gene. All willing family members were counselled and encouraged to be tested. Here we report a kindred formed by 16 individuals with a very severe FAP phenotype. A two-base deletion mutation: c.4393_4394delAG in APC gene and a consequent premature stop codon was detected. DTs were diagnosed in 6 individuals, ranging from 2 to 25 years of age. The causes of death were diverse: gastric cancer, rectal cancer and desmoid tumor. The already described genotype-phenotype correlation has proved its worth in this family, as clinical features reflect the mutation location at 3' end of APC gene. The inheritable and lethal nature of the disease needs a tailored follow up approach in order to reduce mortality, optimize local tumor control, and preserve patients' quality of life.

Difference Between Left-Sided and Right-Sided Colorectal Cancer: A Focused Review of Literature

Colorectal cancer is the third most common cancer worldwide with a high mortality rate at the advanced stages. However, colorectal cancer is not a single type of tumor; its pathogenesis depends on the anatomical location of the tumor and differs between right side and left side of the colon. Tumors in the proximal colon (right side) and distal colon (left side) exhibit different molecular characteristics and histology. In the right-sided tumors, mutations in the DNA mismatch repair pathway are commonly observed; and these tumors generally have a flat histology. In the left-sided tumors, chromosomal instability pathway-related mutations, such as KRAS, APC, PIK3CA, p53 mutations are observed and these tumors demonstrate polypoid-like morphology. Therapy responses are totally different between these tumor entities. Left-sided colorectal cancer (LCRC) patients benefit more from adjuvant chemotherapies such as 5-fluorouracil (5-FU)-based regimes, and targeted therapies such as anti- epidermal growth factor receptor (EGFR) therapy, and have a better prognosis. Right-sided colorectal cancer (RCRC) patients do not respond well to conventional chemotherapies, but demonstrate more promising results with immunotherapies because these tumors have high antigenic load. For the development of effective therapy regimes and better treatment options, it is essential to evaluate right-sided and left-sided tumors as separate entities, and design the therapy regime considering the differences between these tumors.

Familial Colorectal Cancer: Understanding the Alphabet Soup

While most colorectal cancers (CRCs) originate from nonhereditary spontaneous mutations, one-third of cases are familial or hereditary. Hereditary CRCs, which account for < 5% of all CRCs, have identifiable germline mutations and phenotypes, such as Lynch syndrome and familial adenomatous polyposis (FAP). Familial CRCs, which account for up to 30% of CRCs, have no identifiable germline mutation or specific pattern of inheritance, but higher-than-expected incidence within a family. Since the discovery that certain genotypes can lead to development of CRC, thousands of mutations have now been implicated in CRC. These new findings have enhanced our ability to identify at-risk patients, initiate better surveillance, and take preventative measures. Given the large number of genes now associated with hereditary and familial CRCs, clinicians should be familiar with the alphabet soup of genes to provide the highest quality of care for patients and families.

An atypical presentation of small bowel obstruction and perforation secondary to sporadic synchronous intra-abdominal desmoid tumours

•

Intra-abdominal desmoid tumours have a poor prognosis as they can cause intestinal bleeding, obstruction and perforation.

•

The authors report a rare case of small bowel obstruction and perforation secondary to sporadic, synchronous intra-abdominal desmoid tumours.

•

In non-emergency presentations of desmoid tumours, it is essential to exclude hereditary polyposis syndromes.

•

Sporadic intra-abdominal desmoid tumours should be managed in a specialist sarcoma unit.

•

In the presence of polyposis syndromes patients with desmoid tumours should be managed at a specialist colorectal unit.

Introduction

Desmoid tumours (DTs) are rare, soft tissue tumours which account for 0.03% of all neoplasms. They are characteristically locally invasive but do not metastasize. There is frequent association with females of reproductive age, a history of abdominal surgery or trauma and a family history of fibromatoses. Intra-abdominal DTs are infrequently sporadic and more commonly associated with inherited disorders such as familial adenomatous polyposis (FAP), attenuated FAP and Gardener’s syndrome.

Presentation of case

The authors report a rare case of small bowel obstruction and perforation secondary to sporadic, synchronous intra-abdominal DTs in a 54-year old man with atypical symptoms and no risk factors or family history.

Discussion

Intra-abdominal DTs have a worse prognosis as they can cause intestinal bleeding, obstruction and perforation. Due to the rarity of these tumours there are no clear guidelines on their management and this is instead based on small case series from specialist centres. In the non-acute setting patients with sporadic intra-abdominal DTs should be managed in a specialist sarcoma unit by a multidisciplinary team. In the presence of FAP or other polyposis syndromes patients with DTs should be managed at a specialist colorectal unit. Emergent presentations require emergency surgery in suitable candidates.

Conclusion

In non-emergency presentations of DTs, it is essential to exclude FAP, AFAP and other hereditary polyposis syndromes since this affects treatment and subsequent follow-up.

Surgical treatment of familial adenomatous polyposis: Dilemmas and current recommendations

Familial adenomatous polyposis (FAP) is an autosomal dominant inherited syndrome characterized by multiple adenomatous polyps (predisposing to colorectal cancer development) and numerous extracolonic manifestations. The underlying genetic burden generates variable clinical features that may influence operative management. As a precancerous hereditary condition, the rationale of performing a prophylactic surgery is a mainstay of FAP management. The purpose of the present paper is to bring up many controversial aspects regarding surgical treatment for FAP, and to discuss the results and perspectives of the operative choices and approaches. Preferably, the decision-making process should not be limited to the conventional confrontation of pros and cons of ileorectal anastomosis or restorative proctocolectomy. A wide discussion with the patient may evaluate issues such as age, genotype, family history, sphincter function, the presence or risk of desmoid disease, potential complications of each procedure and chances of postoperative surveillance. Therefore, the definition of the best moment and the choice of appropriate procedure constitute an individual decision that must take into consideration patient’s preferences and full information about the complex nature of the disease. All these facts reinforce the idea that FAP patients should be managed by experienced surgeons working in specialized centers to achieve the best immediate and long-term results.

Prevalence and characteristics of MUTYH-associated polyposis in patients with multiple adenomatous and serrated polyps

PURPOSE

The present study aimed to determine the prevalence of MUTYH mutations in patients with multiple colonic polyps and to explore the best strategy for diagnosing MUTYH-associated polyposis (MAP) in these patients.

EXPERIMENTAL DESIGN

This study included 405 patients with at least 10 colonic polyps each. All cases were genetically tested for the three most frequent MUTYH mutations. Whole-gene analysis was performed in heterozygous patients and in 216 patients lacking the three most frequent mutations. Polyps from 56 patients were analyzed for the KRAS-Gly12Cys and BRAF V600E somatic mutations.

RESULTS

Twenty-seven (6.7%) patients were diagnosed with MAP, of which 40.8% showed serrated polyps. The sensitivity of studying only the three common variants was 74.1%. Of 216 patients without any monoallelic mutation in common variants, whole-gene analysis revealed biallelic pathogenic mutation in only one. G396D mutation was associated with serrated lesions and older age at diagnosis. There was a strong association between germinal MUTYH mutation and KRAS Gly12Cys somatic mutation in polyps. BRAF V600E mutation was found in 74% of serrated polyps in MUTYH-negative patients and in none of the polyps of MAP patients.

CONCLUSIONS

We observed a low frequency of MUTYH mutations among patients with multiple adenomatous and serrated polyps. The MAP phenotype frequently included patients with serrated polyps, especially when G396D mutation was involved. Our results show that somatic molecular markers of polyps can be useful in identifying MAP cases and support the need for the complete MUTYH gene analysis only in patients heterozygous for recurrent variants.

Surgical resection for non-familial adenomatous polyposis-related intra-abdominal fibromatosis

BACKGROUND

Intra-abdominal fibromatosis (IAF) in the context of familial adenomatosis polyposis (FAP) is associated with significant morbidity and high recurrence rates after surgical resection. Non-surgical treatments are therefore advocated. This study explored outcomes in patients with IAF not associated with FAP who underwent surgical resection.

METHODS

Data were analysed from a prospectively collected database at a sarcoma tertiary referral centre.

RESULTS

From 2001 to 2011, 15 patients without FAP underwent primary curative surgical resection of IAF. Their median (range) age was 42 (19-64) years. Median tumour size was 18 (8.5-25) cm and weight 1306 (236-2228) g. Complete macroscopic clearance was obtained in all patients. There were no deaths in hospital or within 30 days and only one patient developed a major complication. Median follow-up was 40 (6-119) months. During follow-up two patients developed a recurrence after a disease-free interval of 12 and 16 months.

CONCLUSION

In contrast to FAP-associated IAF, non-FAP-associated IAF has a very low recurrence rate after surgical resection. Surgical resection is therefore advocated as first-line treatment in patients with non-FAP-associated IAF when resection can be performed with low morbidity.