The prognostic relevance of histologic subtype in appendiceal adenocarcinoma

Negative Impact of Systemic Therapy on Survival in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Low-Grade Metastatic Appendiceal Adenocarcinoma

BACKGROUND

Despite studies demonstrating that patients with peritoneal metastases from low-grade appendiceal adenocarcinoma (AA) do not respond well to systemic chemotherapy (SC), patients frequently undergo combination of SC with cytoreductive surgery/hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) regardless of grade.

METHODS

A nationwide retrospective analysis using the National Cancer Database evaluated patients with AA with peritoneal metastasis from 2016 to 2021. Cox proportional hazards model was used to evaluate the impact of SC in addition to CRS/HIPEC on overall survival (OS) stratified by tumor grade.

RESULTS

A total of 1,449 patients were included: 481 low-grade, 428 intermediate-grade, and 540 high-grade tumors. Clinical variables, such as age, sex, and comorbidity index, were similar across tumor grades. Cytoreductive surgery/hyperthermic intraperitoneal chemotherapy without SC was utilized in 65.73% of low-grade cases compared with 41.01% in intermediate-grade and 11.11% in high-grade cases. Systemic chemotherapy was utilized alone in 17.74% and with CRS/HIPEC in 16.53% of low-grade cases. In adjusted survival analysis, addition of SC to CRS/HIPEC was associated with worse OS for patients with low-grade AA (hazard ratio [HR] 2.77, 95% confidence interval [CI] 1.18-6.50) but not for intermediate (HR 1.65, 95% CI 0.82-3.35) and high-grade tumors (HR 1.18, 95% CI 0.67-2.45). The addition of time to definitive surgery variable nullified the negative impact of adding SC to CRS/HIPEC in low-grade AA (HR 1.76, 95% CI 0.68-4.53).

CONCLUSIONS

Negative OS impact of SC may be mediated by delays in effective surgical/intraoperative therapy. If CRS/HIPEC is planned for patients with metastatic low-grade AA, avoiding SC may facilitate earlier surgical intervention and improve survival.

A rare case of FH-deficient renal cell carcinoma with signet ring cells features

Fumarate hydratase-deficient renal cell carcinoma (FH-deficient RCC) is a clinically aggressive tumor with high rates of progression and mortality. A wide range of morphological variations has been observed in FH-deficient RCC, initially described as type 2 papillary RCC or unclassified RCC. Here, we report a case of FH-deficient RCC with rare signet ring cells features. The patient was diagnosed with FH-deficient renal cell carcinoma and suspected to have hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. After 4 months, pulmonary metastasis occurred in the patient. We herein describe the first case of FH-deficient renal tumor with signet ring cells features, which expands the morphological spectrum of this tumor. More importantly, this variant can be a diagnostic pitfall, we emphasize that pathologists should consider not only the diagnosis of metastatic signet ring cell carcinoma and ALK rearrangement renal cell carcinoma but also FH-deficient renal cell carcinoma.

Appendiceal Mucinous Neoplasms: From Clinic to Pathology and Prognosis

Appendiceal mucinous neoplasms have been classified differently over time causing confusion when comparing results between working groups in this field and establishing a prognosis of the disease. A historical perspective of the different classification systems of these tumors is essential for the understanding of the evolution of concepts and histopathological definitions that have led up to the present moment. We carried out a systematic review of the pathological classifications of appendiceal mucinous tumors and how they have included the new criteria resulting from clinical and pathological research. The latest classifications by PSOGI and AJCC 8th edition Cancer Staging have made a great effort to incorporate the new pathological descriptions and develop prognostic groups. The introduction of these new classification systems has posed the challenge of verifying how they adapt to our casuistry and which one defines best the prognosis of our patients. We reclassified our series of patients treated for mucinous appendiceal tumors with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy following the PSOGI and the AJCC 8th edition criteria and concluded that both classifications correspond well with the OS and DFS of these patients, with some advantage relative to the PSOGI classification due to a better histopathological description of the different groups.

Defining stage in mucinous tumours of the appendix with peritoneal dissemination: the importance of grading terminology: systematic review

BACKGROUND

Mucinous appendiceal neoplasms with peritoneal dissemination (PD) show a wide spectrum of clinical behaviour. Histological grade has been correlated with prognosis, but no universally accepted histological grading has been established. The aim of this systematic review was to provide historical insight to understand current grading classifications, basic histopathological features of each category, and to define which classification correlates best with prognosis.

METHODS

MEDLINE and the Cochrane Library were searched for studies that reported survival across different pathological grades in patients with mucinous neoplasm of the appendix with PD treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. PRISMA guidelines were followed.

RESULTS

Thirty-eight studies were included. Ronnett's classification was the most common (9 studies). Classifications proposed by the Peritoneal Surface Oncology Group International (PSOGI) (6 studies) and the seventh or eighth edition of the AJCC (7 studies) are gaining in popularity. Nine studies supported a two-tier, 12 a three-tier, and two a four-tier classification system. Three studies demonstrated that acellular mucin had a better prognosis than low-grade pseudomyxoma peritonei in the PSOGI classification or M1bG1 in the eighth edition of the AJCC classification. Four studies demonstrated that the presence of signet ring cells was associated with a worse outcome than high-grade pseudomyxoma peritonei in the PSOGI classification and M1bG2 in the eighth edition of the AJCC.

CONCLUSION

There is a great need for a common language in describing mucinous neoplasms of the appendix with PD. Evolution in terminology as a result of pathological insight turns the four-tiered PSOGI classification system into a coherent classification option.