Major Surgical Oncology and Complex Benign Tumor Surgery

Being told you have a tumor or "mass" is frightening, whether it turns out to be cancer or a benign (non-cancerous) growth. Surgery remains the cornerstone of cure for most solid tumors of the digestive tract and adrenal glands. For example, about 80% of patients with GIST have localized disease, and complete surgical removal is the standard of care and the only chance of cure (Napolitano et al., Gastrointestinal Oncology, 2024).

Major surgical oncology and complex benign tumor surgery includes:

• Stomach (gastric) cancer. Total, subtotal, or proximal gastrectomy with lymph node removal. See Gastrectomy and Gastric Cancer.
• Gastrointestinal stromal tumors (GIST). Wedge or segmental resection that removes the tumor while preserving as much stomach as possible.
• Benign subepithelial tumors of the stomach and esophagus, such as leiomyomas, schwannomas, and lipomas. These are removed when they cause bleeding, obstruction, or pain, or when the diagnosis is uncertain.
• Adrenal tumors. Hormone-producing adrenal tumors (aldosteronoma, cortisol-producing adenoma, pheochromocytoma), large adrenal masses, and masses suspicious for cancer.
• Complex benign abdominal masses, including tumors near critical structures that require advanced technique.
• Esophagogastric tumors evaluated in coordination with a cancer team. See Esophageal Cancer and Barrett's Esophagus.

Modern tumor surgery is guided by three principles:

• Complete removal with clear (negative) margins
• Organ preservation whenever the cancer allows
• The least invasive approach that is still oncologically sound

Large randomized trials now show that laparoscopic gastrectomy for stomach cancer achieves the same cancer survival as open surgery, with fewer complications in some trials (Hyung et al., Journal of Clinical Oncology, 2020; Etoh et al., JAMA Surgery, 2023).

How the operation works depends on the type of tumor and how it behaves:

• Stomach cancer spreads through the stomach wall and to lymph nodes. Surgery removes the involved portion of the stomach with a margin of healthy tissue, plus the surrounding lymph nodes (D2 lymphadenectomy). This both stages and treats the cancer (Yu et al., JAMA, 2019).
• GISTs grow outward from the wall and rarely spread to lymph nodes. A wedge or segmental resection with negative margins is usually enough. Routine lymph node removal and large operations such as total gastrectomy are rarely needed (National Comprehensive Cancer Network, GIST Guidelines, 2026).
• GISTs are fragile, so the tumor's capsule must stay intact. Tumor rupture sharply increases recurrence risk. In one tertiary series, recurrence was 25% after rupture vs 2.9% without (Anderson et al., Journal of Gastrointestinal Surgery, 2026).
• Hormone-producing adrenal tumors cause high blood pressure, low potassium, Cushing's features, or dangerous adrenaline surges. Removing the gland stops the excess hormone at its source (Rowe et al., CUA Guideline Endorsed by the AUA, 2023).
• Benign subepithelial tumors are removed with targeted, organ-sparing techniques, sometimes combined with intraoperative endoscopy to locate the tumor precisely.

• The best chance of cure. Complete resection is the only curative treatment for localized GIST and most localized stomach cancers (Napolitano et al., Gastrointestinal Oncology, 2024).
• Less invasive, same cancer control:
  • Gastric cancer: KLASS-02 found 3-year relapse-free survival of 80.3% vs 81.3%, laparoscopic vs open (Hyung et al., Journal of Clinical Oncology, 2020).
  • Gastric GIST: in 666 European patients, laparoscopy had lower morbidity (11.3% vs 19.5%) and no loss of cancer control (Piessen et al., Annals of Surgery, 2015).
• Fewer complications:
  • Early complications: 15.7% vs 23.4% after laparoscopic distal gastrectomy for advanced stomach cancer
  • Late complications: 4.7% vs 9.5% (Hyung et al., Journal of Clinical Oncology, 2020)
• Organ preservation. Wedge resection for GIST keeps most of the stomach and avoids the long-term effects of total gastrectomy.
• Hormonal cure. Removing a hormone-secreting adrenal tumor can correct the hormonal syndrome it causes. Minimally invasive adrenalectomy is preferred when feasible (Rowe et al., CUA Guideline Endorsed by the AUA, 2023).
• Faster recovery. Enhanced recovery (ERAS) programs in cancer surgery lowered complications by 40% (RR 0.60) and shortened hospital stays by about 2.7 days (Li et al., International Journal of Nursing Studies, 2026).

• Stomach cancer that is localized or locally advanced and resectable, often after chemotherapy before surgery
• GIST:
  • Larger than 2 cm
  • Smaller than 2 cm with high-risk features, such as irregular borders, cystic spaces, ulceration, or heterogeneity
  • Any size causing bleeding or obstruction
  • Rectal GIST of any size

(Jacobson et al., ACG Clinical Guideline, 2023; Blay et al., Nature Reviews Disease Primers, 2021)

• Adrenal masses:
  • Hormone-producing
  • 4 cm or larger
  • Suspicious on imaging
  • Growing more than 5 mm per year (Rowe et al., CUA Guideline Endorsed by the AUA, 2023; Kebebew, New England Journal of Medicine, 2021)
• Benign tumors causing bleeding, pain, obstruction, or diagnostic uncertainty
• Patients fit for surgery, or able to become fit through prehabilitation

1. Multidisciplinary planning. Imaging, endoscopy, biopsy when appropriate, and tumor board review set the plan. All GIST patients should be evaluated by a multidisciplinary team (National Comprehensive Cancer Network, GIST Guidelines, 2026).
2. Neoadjuvant therapy when indicated:
   • Chemotherapy for many stomach cancers
   • Imatinib or other targeted therapy to shrink a large GIST when it would otherwise require a multi-organ operation (National Comprehensive Cancer Network, GIST Guidelines, 2026)
3. Choice of approach. Laparoscopic, robotic, or open, based on tumor size, location, and invasion of nearby structures.
4. Exposure and staging. The abdomen is inspected for spread before resection begins.
5. Resection:
   • Stomach cancer: gastrectomy with D2 lymphadenectomy
   • GIST: wedge or segmental resection with an intact capsule
   • Adrenal tumor: adrenalectomy
   • Benign subepithelial tumor: enucleation or wedge resection
6. Specimen retrieval in a protective bag to prevent tumor spillage (National Comprehensive Cancer Network, GIST Guidelines, 2026).
7. Reconstruction, such as a Roux-en-Y or Billroth reconstruction after gastrectomy.
8. Intraoperative endoscopy to confirm margins and test the staple line for leaks.
9. ERAS-based recovery, including early walking and early feeding.

Every major operation carries risk. Most risks are reduced by minimally invasive technique, experienced surgeons, and enhanced recovery care:

• Bleeding, infection, and blood clots
• Leaks from staple lines or connections after gastric resection
• Delayed gastric emptying, especially when a tumor sits near the nerves of Latarjet on the lesser curve of the stomach
• Tumor rupture or a positive margin. Careful technique matters, because rupture raises recurrence risk (Anderson et al., Journal of Gastrointestinal Surgery, 2026).
• Dumping syndrome, vitamin B12 and iron deficiency, and weight loss after gastrectomy
• Adrenal-specific risks:
  • Temporary adrenal insufficiency after removing a cortisol-producing tumor, which requires stress-dose steroids (National Comprehensive Cancer Network, Neuroendocrine and Adrenal Tumors Guidelines, 2026)
  • Blood pressure swings during pheochromocytoma surgery, which is why patients receive alpha-blockade beforehand (Kebebew, New England Journal of Medicine, 2021)
• Risk varies by experience. Outcomes differ widely between hospitals and surgeons, even among high-volume providers (Aquina et al., Cancer, 2021).

• Wedge resection of a GIST or benign tumor: usually 1–2 nights in the hospital. Many laparoscopic patients go home on postoperative day 1.
• Adrenalectomy: usually 1 night.
• Gastrectomy: usually 4–7 days, depending on the extent of resection.
• Enhanced recovery in major cancer surgery lowered overall complications from 33% to 20% and shortened median stays from 5 to 4 days (Marcus et al., Annals of Surgical Oncology, 2019).
• Return to work: 2–3 weeks after minimally invasive tumor resection and 4–8 weeks after gastrectomy.
• Adjuvant therapy: faster recovery allows earlier start of chemotherapy or targeted therapy when it's needed.

• Gastric GIST. At a tertiary center, 5-year disease-specific survival was 98.5% and recurrence-free survival 95.9%. Recurrences concentrated in high-risk, large, or ruptured tumors (Anderson et al., Journal of Gastrointestinal Surgery, 2026).
• Stomach cancer. Survival depends mainly on stage. Laparoscopic distal gastrectomy for advanced disease achieved 5-year relapse-free survival of 75.7% vs 73.9% for open surgery (Etoh et al., JAMA Surgery, 2023).
• Benign tumors. After complete removal, cure is expected.
• Functional adrenal tumors. Hormone excess resolves after removal. Some patients still need medication for underlying high blood pressure.
• Surveillance. Ongoing imaging and follow-up are tailored to the tumor's risk.

More in General and Minimally Invasive Surgery

Related procedures: Robotic Surgery, Laparoscopic Cholecystectomy, Hernia Repair, Inguinal Hernia Repair, Appendectomy, Splenectomy. For an overview of all options, see Minimally Invasive Surgery.

Conditions treated: Gastric Cancer, Gastrointestinal Stromal Tumor (GIST), Adrenal Tumors, Esophageal Cancer.

Expected Health Improvements

• Aldosterone-producing tumors. Removal corrects excess aldosterone and low potassium, and blood pressure often improves (Rowe et al., CUA Guideline Endorsed by the AUA, 2023).
• Cortisol-producing tumors with Cushing's syndrome should be removed. Younger patients with mild autonomous cortisol secretion and worsening metabolic problems may be considered after shared decision-making (Rowe et al., CUA Guideline Endorsed by the AUA, 2023).
• Pheochromocytoma. Removal stops dangerous adrenaline surges (Kebebew, New England Journal of Medicine, 2021).
• Bleeding GIST or benign tumor. Removal resolves the iron-deficiency anemia caused by chronic blood loss.

After tumor surgery, the focus is on preventing recurrence and planning surveillance:

• Risk stratification. Every GIST is classified by size, mitotic rate, location, and rupture status. These factors predict recurrence.
• Adjuvant targeted therapy. Imatinib is recommended for GIST patients at substantial risk of recurrence (Rice and Rattner, JOMI, 2024).
• Molecular testing. It guides drug selection, because some mutations don't respond to imatinib. For example, avapritinib is used for PDGFRA exon 18 mutations (National Comprehensive Cancer Network, GIST Guidelines, 2026).
• Imaging surveillance is spaced according to tumor risk.
• Oncologic technique prevents local recurrence: intact capsule, negative margins, and bagged retrieval.

Dr. Nestor de la Cruz-Muñoz, MD, FACS, DABOM brings decades of advanced laparoscopic and robotic gastrointestinal surgery to complex tumor operations. That includes thousands of foregut and stomach operations, the anatomy where GISTs, gastric cancers, and subepithelial tumors arise.

• Educator of surgeons. He served for 10 years as a bariatric surgery fellowship program director, training the next generation of advanced GI surgeons in precise, minimally invasive technique.
• Organ-sparing philosophy. He removes tumors with clear margins and an intact capsule while preserving healthy stomach, avoiding a total gastrectomy when guidelines say it isn't needed.
• Multidisciplinary partnership. Plans are coordinated with medical oncology, gastroenterology and advanced endoscopy, endocrinology, radiology, and pathology through tumor board review.
• Complete foregut expertise. Patients have access to the full range of foregut operations, including Gastrectomy, Gastric Outlet Obstruction Surgery, Surgical Management of Bleeding Ulcer, and Foregut Surgery.
• Enhanced recovery and prehabilitation built in, so patients arrive at surgery stronger and leave the hospital sooner.

For tumor resections, Dr. de la Cruz-Muñoz relies on over 25 years in practice and over 15,000 minimally invasive procedures, a record that includes complex foregut, hernia, gallbladder and abdominal operations as well as bariatric surgery.

• Tumors near the gastroesophageal (GE) junction require techniques that protect the lower esophageal sphincter to prevent new reflux.
• Proximal gastrectomy carries a higher risk of reflux. Reconstruction is chosen to minimize it.
• Patients with existing reflux, hiatal hernia, or Barrett's esophagus can sometimes have them addressed in the same operation. See Hiatal Hernia Repair and GERD / Acid Reflux.

• Positive microscopic margin (R1) after GIST surgery. Re-resection is generally not indicated (National Comprehensive Cancer Network, GIST Guidelines, 2026).
• Recurrent or metastatic GIST. Targeted therapy comes first. Surgery may be considered for limited disease that responds to therapy, for isolated progression, or for bleeding or obstruction (National Comprehensive Cancer Network, GIST Guidelines, 2026).
• Post-gastrectomy problems such as strictures, outlet obstruction, or bile reflux may need revisional surgery. See Gastric Outlet Obstruction Surgery and Esophageal Dilation.

Cancer and medically necessary tumor surgery is covered by most insurers, including Medicare. The record should document:

• Tissue diagnosis or imaging findings consistent with a tumor that needs removal
• Staging studies: CT, endoscopic ultrasound, PET when indicated
• Hormonal testing for adrenal masses
• A multidisciplinary treatment plan when chemotherapy or targeted therapy is involved

• Imaging and endoscopy: CT, endoscopic ultrasound, and biopsy when it will change management. Biopsy is avoided for GISTs that can be removed directly, because incisional biopsy should not be performed (National Comprehensive Cancer Network, GIST Guidelines, 2026).
• Adrenal workup. Testing for cortisol excess and pheochromocytoma in every patient, plus aldosterone testing in patients with high blood pressure (Kebebew, New England Journal of Medicine, 2021).
• Pheochromocytoma: alpha-blockade, and beta-blockade if needed, before surgery.
• Targeted therapy timing:
  • Imatinib can be stopped right before surgery.
  • Other kinase inhibitors are stopped at least 1 week beforehand (National Comprehensive Cancer Network, GIST Guidelines, 2026).
• Prehabilitation: exercise, protein, smoking cessation, and diabetes control.
• GLP-1 medications are managed as directed by the anesthesia team.

Cancer and surgery both break down muscle. Patients who enter surgery stronger recover better:

• Multimodal prehabilitation combines exercise, nutrition, and psychological support:
  • Major abdominal cancer surgery: 27 randomized trials (2,532 patients) showed 40% lower odds of complications (Soh et al., Annals of Surgical Oncology, 2025).
  • GI cancer surgery: overall complications fell 33% (RR 0.67), and severe complications fell as well (Zheng et al., American Journal of Physical Medicine & Rehabilitation, 2026).
• Protein-forward nutrition before and after surgery, with supplements when intake is low
• Early walking and gradual resistance training after surgery
• Lifelong B12 and iron monitoring after gastrectomy

• Wedge resection or adrenalectomy: liquids the day of surgery and regular food within days.
• Gastrectomy:
  • Small, frequent, protein-rich meals (6 per day)
  • Liquids separated from meals
  • Avoiding concentrated sugars to prevent dumping syndrome
• Lifelong supplements after total gastrectomy: vitamin B12, iron, calcium, and vitamin D
• Dietitian follow-up to track weight and protein intake

After tumor surgery, weight and nutrition changes depend on the operation:

• Wedge resection or adrenalectomy: little to no lasting weight change is expected.
• Subtotal or total gastrectomy: weight loss is common in the first 6–12 months. Patients are guided by a dietitian toward stable weight and protein intake.
• Cancer-related weight loss before surgery is addressed with nutritional prehabilitation.

• Day of surgery: walk.
• Weeks 1–4: daily walking. No lifting over 15–20 lbs.
• After 4–6 weeks: gradual return to resistance training and full activity.
• During chemotherapy or targeted therapy: continued moderate exercise to preserve strength and reduce fatigue.

Complex tumor surgery for patients from abroad starts with a virtual review of pathology, imaging and staging. Hospital stays vary widely, from a few days to two weeks or more, so travel plans are made once the operation is defined. We coordinate with your home oncology team for any treatment before or after surgery.