The first 60 days: Appendiceal cancer and pseudomyxoma peritonei
Rare tumours of the appendix that range from slow mucin-producing growths that fill the abdomen (pseudomyxoma peritonei) to aggressive adenocarcinomas. The slow forms are treated by extensive surgery with heated chemotherapy in the abdomen; the fast ones like colon cancer. Below, week by week, is what OnCo's record of Appendiceal cancer and pseudomyxoma peritonei says about the first two months: the order is typical, the timing is yours to ask about. Sections appear only where the record has something to say. Orientation, not medical advice.
What happens now
Staging tests establish exactly what and where the cancer is. Everything else follows from the answers.
Ask which of these were tested and what the results were; see the report reader for what each value means.
These specialties appear in the standard of care for this cancer. In most centres they meet weekly as a tumour board to agree each plan; you can ask when yours was discussed and what was decided.
- SurgeonNamed in the standard of care for: Localised LAMN / adenocarcinoma, Pseudomyxoma peritonei / peritoneal disease.
- Medical oncologistNamed in the standard of care for: Localised LAMN / adenocarcinoma, Pseudomyxoma peritonei / peritoneal disease, High-grade or unresectable peritoneal disease.
A second opinion from a centre that treats many similar cases is normal, not rude; the standard of care tells you what to compare it against.
Each row is a setting from the standard of care, in the order it usually arises. Not all will apply to you; your stage and biomarkers decide which do. The guideline grade, where recorded, says how strong the evidence is.
- 1.Localised LAMN / adenocarcinomaNCCN category Category 2A, NCCN Guidelines: Colon Cancer (appendiceal section)
Appendicectomy (LAMN without perforation) or right hemicolectomy (adenocarcinoma, goblet cell); adjuvant chemotherapy for node-positive adenocarcinoma by colorectal analogy.
FOLFOX/CAPOX ± bevacizumab; systemic chemotherapy has no proven benefit in low-grade disease (randomised 2024).
Cytoreductive surgery with HIPEC at a peritoneal-surface-malignancy centre; repeat CRS for recurrence when feasible.
Generated from this cancer's standard of care, biomarkers and open problems. Take the group that matches where you are. To tick, add your own and print, open the one-page appointment sheet.
Newly diagnosed
- What is my exact diagnosis, stage, and grade, and which tests established them?Everything else follows from an accurate stage and subtype.
- Which biomarkers have been tested on my tumour (for example PSOGI histologic grade, Peritoneal cancer indexand completeness of cytoreduction, GNAS, KRAS, TP53, SMAD4, CEA, CA19-9, CA-125, MSI), and what were the results?These results decide eligibility for targeted therapy, immunotherapy, and trials.
- Which subtype is my cancer, and does that change the recommended treatment?Recognised subtypes for this cancer include LAMN / HAMN, Pseudomyxoma peritonei, Mucinous and non-mucinous adenocarcinoma.
- Is germline (inherited) genetic testing recommended for me or my family?Inherited variants can change treatment and matter for relatives.
Localised LAMN / adenocarcinoma
- For my situation (localised lamn / adenocarcinoma), which of the standard options do you recommend and why?Guideline options include: Appendicectomy (LAMN without perforation) or right hemicolectomy (adenocarcinoma, goblet cell); adjuvant chemotherapy for node-positive adenocarcinoma by colorectal analogy.
- Am I a candidate for FOLFOX (5-FU, leucovorin, oxaliplatin), CAPOX (capecitabine, oxaliplatin), and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Pseudomyxoma peritonei / peritoneal disease
- For my situation (pseudomyxoma peritonei / peritoneal disease), which of the standard options do you recommend and why?Guideline options include: Cytoreductive surgery with HIPEC at a peritoneal-surface-malignancy centre; repeat CRS for recurrence when feasible.
High-grade or unresectable peritoneal disease
- For my situation (high-grade or unresectable peritoneal disease), which of the standard options do you recommend and why?Guideline options include: FOLFOX/CAPOX ± bevacizumab; systemic chemotherapy has no proven benefit in low-grade disease (randomised 2024).
- Am I a candidate for FOLFOX (5-FU, leucovorin, oxaliplatin), CAPOX (capecitabine, oxaliplatin), Bevacizumab, and what side effects should I expect?Knowing the expected toxicities helps you plan work, family, and supportive care.
Any stage
- Are there clinical trials I could join, for example of HIPEC / PIPAC (intraperitoneal chemotherapy), FOLFOX (5-FU, leucovorin, oxaliplatin)?Trials are how the next standard of care is set; asking early keeps options open.
- Would a second opinion at a high-volume centre change anything, and can you help arrange it?Rare or high-stakes decisions benefit from a centre that treats many similar patients.
- What supportive care (symptom control, nutrition, exercise, mental health, financial help) is available from the start?Supportive care improves quality of life and helps patients complete treatment.
- I read that “No effective systemic therapy for high-grade or signet-ring disease”. How does that affect my plan?Open problems are where trials and second opinions matter most.
- I read that “Selection for CRS-HIPEC and management of recurrence after maximal surgery”. How does that affect my plan?Open problems are where trials and second opinions matter most.
Trials open now for this cancer in OnCo, largest phase first. Joining a trial is a decision like any other: ask what the comparison arm is, whether a placebo is used, and what happens if you leave. The cancer page searches ClinicalTrials.gov live for more.
Much of what helps in the first weeks is free if you know to ask: testing, helplines, rides and lodging, second opinions, trial travel.
- Appendiceal cancer and pseudomyxoma peritonei: the full pageRare tumours of the appendix that range from slow mucin-producing growths that fill the abdomen (pseudomyxoma peritonei) to aggressive adenocarcinomas. The slow forms are treated by extensive surgery with heated chemotherapy in the abdomen; the fast ones like colon cancer.
- One-page appointment sheetYour questions, the words you may hear, what to bring, and space for the answers. Print it.
- Treatment sequencingWhich treatment tends to follow which, line by line.
- NavigatorStandard of care for your stage, what you have tried, and trials near you.
- Colectomy: Removing the part of the colon containing the cancer along with its blood supply and lymph nodes, then joining the ends.
- Peritoneal metastasis: Spread across the lining of the abdomen, the most common way stomach cancer recurs and the hardest to treat.
- Rare cancers: Rare cancers are those with fewer than about 6 new cases per 100,000 people per year.
Every term links to the glossary.