Serum Tumor Markers and Outcomes in Patients With Appendiceal Adenocarcinoma.

Importance: Serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 125 (CA125) have been useful in the management of gastrointestinal and gynecological cancers; however, there is limited information regarding their utility in patients with appendiceal adenocarcinoma. Objective: To assess the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes and pathologic and molecular features in patients with appendiceal adenocarcinoma. Design, Setting, and Participants: This is a retrospective cohort study at a single tertiary care comprehensive cancer center. The median (IQR) follow-up time was 52 (21-101) months. Software was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least 1 tumor marker measured at MD Anderson between March 2016 and May 2023. Data were analyzed from January to December 2023. Main Outcomes and Measures: Association of serum tumor markers with survival in patients with appendiceal adenocarcinoma. Cox proportional hazards regression analyses were also performed to assess associations between clinical factors (serum tumor marker levels, demographics, and patient and disease characteristics) and patient outcomes (overall survival). Results: A total of 1338 patients with appendiceal adenocarcinoma were included, with a median (range) age at diagnosis of 56.5 (22.3-89.6) years. The majority of the patients had metastatic disease (1080 patients [80.7%]). CEA was elevated in 742 of the patients tested (56%), while CA19-9 and CA125 were elevated in 381 patients (34%) and 312 patients (27%), respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; elevated vs normal was 81% vs 95% for CEA (hazard ratio [HR], 4.0; 95% CI, 2.9-5.6), 84% vs 92% for CA19-9 (HR, 2.2; 95% CI, 1.4-3.4), and 69% vs 93% for CA125 (HR, 4.6; 95% CI, 2.7-7.8) (P < .001 for all). Quantitative evaluation of tumor markers was associated with outcomes. Patients with highly elevated (top 10th percentile) CEA, CA19-9, or CA125 had markedly worse survival, with 5-year survival rates of 59% for CEA (HR, 9.8; 95% CI, 5.3-18.0), 64% for CA19-9 (HR, 6.0; 95% CI, 3.0-11.7), and 57% for CA125 (HR, 7.6; 95% CI, 3.5-16.5) (P < .001 for all). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease, elevated CEA, CA19-9, or CA125 were all still associated worse survival (HR for CEA, 3.4; 95% CI, 2.5-4.8; P < .001; HR for CA19-9, 1.8; 95% CI, 1.2-2.7; P = .002; and HR for CA125, 3.9; 95% CI, 2.4-6.4; P < .001). Interestingly, tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high-grade tumors relative to low-grade tumors (mean value, 18.3 vs 15.0; difference, 3.3; 95% CI, 0.9-3.7; P < .001). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with an 11-fold increased risk of death in patients with all 3 tumor markers elevated relative to those with none elevated. Somatic mutations in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9. Conclusions and Relevance: In this retrospective study of serum tumor markers in patients with appendiceal adenocarcinoma, CEA, CA19-9, and CA125 were associated with overall survival in appendiceal adenocarcinoma. Given their value, all 3 biomarkers should be included in the initial workup of patients with a diagnosis of appendiceal adenocarcinoma.

Repeat Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy for Recurrent Mucinous Appendiceal Adenocarcinoma: A Viable Treatment Strategy with Demonstrable Benefit.

INTRODUCTION: Many patients with mucinous appendiceal adenocarcinoma experience peritoneal recurrence despite complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Prior work has demonstrated that repeat CRS/HIPEC can prolong survival in select patients. We sought to validate these findings using outcomes from a high-volume center. PATIENTS AND METHODS: Patients with mucinous appendiceal adenocarcinoma who underwent CRS/HIPEC at MD Anderson Cancer Center between 2004 and 2021 were stratified by whether they underwent CRS/HIPEC for recurrent disease or as part of initial treatment. Only patients who underwent complete CRS/HIPEC were included. Initial and recurrent groups were compared. RESULTS: Of 437 CRS/HIPECs performed for mucinous appendiceal adenocarcinoma, 50 (11.4%) were for recurrent disease. Patients who underwent CRS/HIPEC for recurrent disease were more often treated with an oxaliplatin or cisplatin perfusion (35%/44% recurrent vs. 4%/1% initial, p < 0.001), had a longer operative time (median 629 min recurrent vs. 511 min initial, p = 0.002), and had a lower median length of stay (10 days repeat vs. 13 days initial, p < 0.001). Thirty-day complication and 90-day mortality rates did not differ between groups. Both cohorts enjoyed comparable recurrence free survival (p = 0.82). Compared with patients with recurrence treated with systemic chemotherapy alone, this select cohort of patients undergoing repeat CRS/HIPEC enjoyed better overall survival (p < 0.001). CONCLUSIONS: In appropriately selected patients with recurrent appendiceal mucinous adenocarcinoma, CRS/HIPEC can provide survival benefit equivalent to primary CRS/HIPEC and that may be superior to that conferred by systemic therapy alone in select patients. These patients should receive care at a high-volume center in the context of a multidisciplinary team.

Treatment Variation and Long-Term Outcomes of Low-Grade Appendiceal Neoplasms.

BACKGROUND: Heterogenous nomenclature describing appendiceal neoplasms has added to uncertainty around their appropriate treatment. Although a recent consensus has established the term low-grade appendiceal neoplasm (LAMN), we hypothesize that significant variation remains in the treatment of LAMNs. METHODS: We retrospectively reviewed our prospectively maintained appendiceal registry, identifying patients with LAMNs from 2009 to 2019. We assessed variability in treatment, including whether patients underwent colectomy, spread of disease at presentation, and long-term outcomes. RESULTS: Of 136 patients with LAMNs, 88 (35%) presented with localized disease and 48 (35%) with disseminated peritoneal disease. Median follow-up was 2.9 years (IQR 1.9-4.4), and 120 (88%) patients underwent pre-referral surgery. Among 26 pre-referral colectomy patients, 23 (88%) were performed for perceived oncologic need/nodal evaluation; no nodal metastases were identified. In patients with resected LAMNs without radiographic evidence of disseminated disease, 41 (47%) underwent second look diagnostic laparoscopy (DL) to evaluate for occult metastases. No peritoneal metastases were identified. Patients with disseminated disease were treated with cytoreductive surgery/heated intraperitoneal chemotherapy (CRS/HIPEC). For patients undergoing CRS/HIPEC, 5-year recurrence-free survival was 94% (95% CI 81-98%). For patients with localized disease, 5-year RFS was 98% (95% CI 85-99%). CONCLUSIONS: Significant variation exists in treatment patterns for LAMNs, particularly prior to referral to a high-volume center. Patients frequently underwent colectomy without apparent oncologic benefit. In the current era of high-quality cross sectional imaging, routine use of DL has low yield and is not recommended. Recurrence in this population is rare, and low-intensity surveillance can be offered. Overall prognosis is excellent, even with peritoneal disease.

The Clinical Significance of CEA, CA19-9, and CA125 in Management of Appendiceal Adenocarcinoma.

Importance: Serum tumor markers CEA, CA19-9, & CA125 have been useful in the management of gastrointestinal and gynecological cancers, however there is limited information regarding their utility in patients with appendiceal adenocarcinoma. Objective: Assessing the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes, pathologic, and molecular features in patients with appendiceal adenocarcinoma. Design: This is a retrospective study with results reported in 2023. The median follow-up time was 43 months. Setting: Single tertiary care comprehensive cancer center. Participants: Under an approved Institutional Review Board protocol, the Palantir Foundry software system was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least one tumor marker measured at MD Anderson between 2016 and 2023. Results: A total of 1,338 patients with appendiceal adenocarcinoma were included, with a median age of 56.5 years. The majority of the patients had metastatic disease (80.7%). CEA was elevated in more than half of the patients tested (56%), while CA19-9 and CA125 were elevated in 34% and 27%, respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; 82% vs 95%, 84% vs 92%, and 69% vs 93% elevated vs normal for CEA, CA19-9, and CA125 respectively (all p<0.0001). Quantitative evaluation of tumor markers increased prognostic ability. Patients with highly elevated (top 10th percentile) CEA, CA19-9 or CA125 had markedly worse survival with 5-year survival rates of 59%, 64%, and 57%, respectively (HR vs. normal : 9.8, 6.0, 7.6, all p<0.0001). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease elevated CEA, CA19-9 or CA125 were all still associated worse survival (HR vs. normal : 3.4, 1.8, 3.9, p<0.0001 for CEA and CA125, p=0.0019 for CA19-9). Interestingly tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high relative to low-grade tumors (18.3 vs. 15.0, p=0.0009). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with a 11-fold increased risk of death in patients with all three tumor markers elevated relative to those with none elevated. Mutation in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9. Conclusions: These findings demonstrate the utility of measuring CEA, CA19-9, and CA125 in the management of appendiceal adenocarcinoma. Given their prognostic value, all three biomarkers should be included in the initial workup of patients diagnosed with appendiceal adenocarcinoma.

Should Sentinel Lymph Node Biopsy Be Performed for All T1b Melanomas in the New 8th Edition American Joint Committee on Cancer Staging System?

BACKGROUND: In the 8th edition of the American Joint Committee on Cancer melanoma staging system, the T1b category has been redefined based solely on thickness and ulceration. National Comprehensive Cancer Network guidelines recommend consideration of sentinel lymph node biopsy (SLNB) for all patients with T1b melanomas (0.8 to 1.0 mm thick). We hypothesized that the new staging system would lead to excessive use of SLNB in patients with non-ulcerated T1b melanomas with a low risk of positive sentinel lymph nodes. STUDY DESIGN: The National Cancer Database 2015 Melanoma Public Use File was used to select patients undergoing SLNB for thin T1 cutaneous melanoma from 2010 to 2015. Clinicopathologic risk factors for having a positive SLNB were evaluated. Univariable and multivariable logistic regression models and classification and regression tree analysis were performed to identify groups with high and low risk of positive SLNB. RESULTS: We selected patients undergoing SLNB without ulceration with thickness 0.75 to 1.04 mm, staged T1b in the new 8th edition American Joint Committee on Cancer by thickness criteria alone (6,894 patients). Independent risk factors for a positive sentinel lymph node were age 56 years or younger (odds ratio [OR] 1.74; 95% CI 1.38 to 2.17), thickness 1.0 vs 0.8 to 0.9 mm (OR 1.36; 95% CI 1.09 to 1.70), female sex (OR 1.36; 95% CI 1.09 to 1.69), and mitotic rate ≥1/mm2 (OR 2.01; 95% CI 1.54 to 2.64). Classification and regression tree analysis identified 2 groups based on age, mitotic rate, and thickness with a risk of positive SLNB <5%. These 2 groups made up 55% of T1b, nonulcerated melanoma patients who underwent SLNB. CONCLUSIONS: The new 8th edition American Joint Committee on Cancer melanoma staging system T1b category should not be used to determine use of SLNB in thin melanoma, as more than one half of T1b lesions without ulceration have a low risk of positive sentinel lymph nodes.