Listing 13.16 Esophagus and Stomach Cancer in 2026

Esophageal and gastric cancers together cause enormous morbidity worldwide. The American Cancer Society projects 22,410 new US esophageal cancer cases (17,470 men, 4,940 women) with 16,610 deaths in 2026. Stomach cancer projects 26,890 new cases (16,160 men, 10,730 women) with 10,880 deaths. Both cancers have poor 5-year survival at diagnosis (about 22% overall for esophageal, 36% for stomach) largely because most present at advanced stages.

SSA Listing 13.16 covers both cancers under a single section with three paragraphs. This walkthrough covers histologic subtypes, HER2 and claudin 18.2 biomarker testing, the checkpoint inhibitor revolution in gastroesophageal cancer, and the surgical residuals that dominate the CDR for patients who reach the 3-year survival mark.

The listing text

Paragraph A: Inoperable or unresectable

Primary tumor that is inoperable, unresectable, or has extended locally beyond the organ of origin meets Paragraph A. For esophagus this includes T4b invasion into trachea, aorta, vertebra, or other unresectable adjacent structures. For stomach this includes T4b invasion into pancreas, spleen, transverse colon, or other adjacent organs. Also included: patients who are not surgical candidates due to comorbidities regardless of tumor stage, and diffuse-type gastric cancer with extensive submucosal spread (linitis plastica).

Paragraph B: Recurrent disease

Recurrent esophageal or gastric cancer after prior treatment qualifies. Recurrence rates are high - about 40-50% of resected gastroesophageal cancer recurs within 5 years, most within 24 months. Anastomotic recurrence, regional recurrence, and distant recurrence all count.

Paragraph C: Metastases beyond regional nodes

Regional nodes for esophageal cancer include periesophageal, paratracheal, subcarinal, aortopulmonary, and celiac axis nodes. For gastric cancer regional nodes include perigastric, left gastric, hepatic, splenic, celiac, and various other stations per the Japanese Gastric Cancer Association mapping. Metastases beyond these to distant organs (liver, lung, peritoneum, distant nodes including left supraclavicular Virchow node, and periumbilical Sister Mary Joseph node) meet Paragraph C.

Histologic subtypes

Esophageal adenocarcinoma (65% of US esophageal cancer)

Dominant subtype in Western countries. Arises typically in the distal esophagus from Barrett esophagus (metaplastic columnar epithelium replacing normal squamous mucosa in the setting of chronic reflux). Major risk factors: chronic GERD, obesity, male sex, white ethnicity, tobacco. Rising incidence in US over past 40 years paralleling obesity epidemic.

Esophageal squamous cell carcinoma (35% of US, 90%+ worldwide)

Dominant subtype globally. Arises typically in mid or upper esophagus. Major risk factors: tobacco, alcohol (especially in combination), hot beverage consumption, poor nutritional status, achalasia, prior head/neck radiation, tylosis, Plummer-Vinson syndrome. Higher incidence in African American men.

Gastroesophageal junction (GEJ) tumors

Siewert classification:

• Type I: 1-5 cm above GEJ (esophageal adenocarcinoma)
• Type II: within 1 cm above to 2 cm below GEJ (true GEJ)
• Type III: 2-5 cm below GEJ (gastric cardia adenocarcinoma)

Type I treated as esophageal cancer, Type III as gastric cancer, Type II individualized.

Gastric adenocarcinoma subtypes

Lauren classification:

• Intestinal type: gland-forming, better differentiated, associated with H. pylori chronic gastritis, better prognosis
• Diffuse type: signet ring cells, poorly cohesive, worse prognosis, includes hereditary diffuse gastric cancer (CDH1 mutation)
• Mixed type: features of both

Linitis plastica is an aggressive diffuse-type variant with extensive submucosal infiltration causing rigid non-distensible stomach ("leather bottle" appearance).

Gastric cancer molecular subtypes (TCGA)

• EBV-positive (9%) - high PD-L1 expression, better prognosis, immunotherapy responsive
• Microsatellite instability-high (22%) - immunotherapy responsive
• Genomically stable (20%) - typically diffuse-type, worse prognosis
• Chromosomal instability (50%) - intestinal-type, HER2 amplification common

Biomarker testing (mandatory in 2026)

• HER2: IHC + FISH reflex. HER2-positive in about 20% of gastric/GEJ adenocarcinoma. Targets trastuzumab + pembrolizumab (first-line per KEYNOTE-811) and fam-trastuzumab deruxtecan (T-DXd) second-line.
• PD-L1 CPS: nivolumab + FOLFOX for CPS 5+ (CheckMate 649). Pembrolizumab for esophageal squamous cell CPS 10+.
• Claudin 18.2: IHC. Positive in about 38% of gastric adenocarcinoma. Targets zolbetuximab (approved 2024 based on SPOTLIGHT and GLOW trials).
• MSI/MMR: MSI-high in 22% of gastric cancer. Pembrolizumab responsive.
• NTRK, RET fusions, EGFR: rare but actionable
• FGFR2b amplification: bemarituzumab in trials
• EBV testing: EBER in situ hybridization for EBV-positive tumors

The Compassionate Allowance overlay

Esophageal cancer and stomach cancer with distant metastases are on the CAL list. Advanced disease automatically flags for expedited processing (14-30 day initial decisions).

Modern treatment

Perioperative FLOT (docetaxel + oxaliplatin + fluorouracil + leucovorin)

Standard for resectable gastric/GEJ adenocarcinoma since FLOT4 trial (2019). 4 cycles pre-op + 4 cycles post-op. Improved OS vs older ECF/ECX regimens.

CROSS regimen for resectable esophageal cancer

Weekly carboplatin + paclitaxel + 41.4 Gy radiation followed by esophagectomy. Standard for locally advanced esophageal cancer since CROSS trial (2012). Adjuvant nivolumab per CheckMate 577 for patients with residual disease at surgery.

Nivolumab + FOLFOX (CheckMate 649)

First-line for advanced HER2-negative gastric/GEJ adenocarcinoma with PD-L1 CPS 5+. Standard since 2021.

Pembrolizumab + trastuzumab + chemo (KEYNOTE-811)

First-line for HER2-positive advanced gastric/GEJ adenocarcinoma. Standard since 2021.

Zolbetuximab (SPOTLIGHT and GLOW)

Monoclonal antibody targeting claudin 18.2. Combined with mFOLFOX6 or CAPOX for first-line advanced HER2-negative, claudin 18.2-positive gastric/GEJ adenocarcinoma. FDA approved 2024. Toxicities: nausea/vomiting (severe, requires premedication), infusion reactions.

Fam-trastuzumab deruxtecan (T-DXd, Enhertu)

HER2-targeted ADC with topoisomerase I inhibitor payload. Second-line for HER2-positive gastric/GEJ per DESTINY-Gastric01. Toxicities: interstitial lung disease (potentially fatal, requires monitoring), neutropenia, nausea, alopecia.

Pembrolizumab + chemo (KEYNOTE-590 esophageal)

First-line for advanced esophageal cancer regardless of histology.

Nivolumab + ipilimumab (CheckMate 648 esophageal squamous)

Chemo-free IO combination for esophageal squamous cell cancer.

Surgical residuals for the CDR

Esophagectomy approaches

• Ivor Lewis (right thoracotomy + laparotomy, intrathoracic anastomosis) - most common for distal esophageal/GEJ
• McKeown (right thoracotomy + laparotomy + left neck, cervical anastomosis)
• Transhiatal (laparotomy + left neck, no thoracotomy)
• Minimally invasive/robotic variants of all approaches

Universal residuals: dysphagia (near-universal, some resolve, some persist), gastroesophageal reflux (severe due to loss of LES), dumping syndrome (early or late), delayed gastric emptying, chronic weight loss and inability to maintain adequate nutrition, chronic diarrhea, chronic anemia (vitamin B12, iron), aspiration risk, anastomotic strictures requiring repeated dilation.

Total gastrectomy with Roux-en-Y esophagojejunostomy

Standard for proximal gastric tumors. Residuals: severe dumping syndrome (both early and late), permanent B12 deficiency (requires monthly injections), iron deficiency anemia, calcium and vitamin D malabsorption with osteoporosis, dramatic weight loss (30-50 lbs common), postprandial abdominal pain, chronic diarrhea, small intestinal bacterial overgrowth, marginal ulcer at anastomosis.

Subtotal gastrectomy with Billroth I or II reconstruction

For distal gastric tumors. Residuals similar to but generally less severe than total gastrectomy. Bile reflux gastritis common with Billroth II.

Nutritional support

Many patients require:

• Feeding jejunostomy tube (often permanent)
• Small frequent meals
• Elemental or high-protein liquid supplementation
• Pancreatic enzyme supplementation
• Chronic B12 injections after gastrectomy
• Chronic iron, calcium, vitamin D supplementation

Cancer cachexia

Nearly universal at diagnosis of advanced esophageal or gastric cancer. Involuntary weight loss exceeding 5% of body weight over 6 months, muscle wasting, anorexia. Different from starvation - driven by tumor-derived cytokines and metabolic dysregulation. Difficult to reverse. Emerging pharmacologic agents (anamorelin, olanzapine) show modest benefit.

Worked case examples

Case 1: David, 63, Michigan, T3N2 distal esophageal adenocarcinoma post-CROSS + Ivor Lewis

David had 20-year history of GERD, obese (BMI 34), never had EGD until presenting with dysphagia and 25 lb weight loss January 2026. EGD found circumferential distal esophageal tumor. Pathology: HER2-negative adenocarcinoma. Staging PET-CT: T3N2M0. Received CROSS regimen (chemo + 41.4 Gy) then Ivor Lewis esophagectomy April 2026. Final pathology: ypT2N1 with 2 of 22 positive nodes. Adjuvant nivolumab per CheckMate 577.

SSDI application filed May 2026. Listing 13.16C met (regional nodal disease at initial staging plus residual disease). Approved 4 weeks at Michigan DDS. Persistent dysphagia requiring endoscopic dilation every 3-4 months. Chronic reflux despite BID PPI. Dumping syndrome causing postprandial diaphoresis and diarrhea. Weight remained 40 lbs below baseline at 12 months.

Case 2: Maria, 58, Texas, HER2-positive metastatic gastric cancer on first-line pembro + trastuzumab + FOLFOX

Maria presented with epigastric pain, early satiety, and iron deficiency anemia October 2025. EGD found large fundic mass. Pathology: gastric adenocarcinoma, HER2 3+ by IHC, claudin 18.2 negative, PD-L1 CPS 8, MSS. Staging: liver metastases and peritoneal carcinomatosis with malignant ascites. Started pembrolizumab + trastuzumab + FOLFOX per KEYNOTE-811.

SSDI application filed November 2025. CAL for metastatic gastric cancer. Approved 13 days at Texas DDS. Partial response at 4 months. Ongoing therapy. Chronic ascites requiring monthly paracentesis. Cachexia despite oral nutrition.

Case 3: Robert, 71, Ohio, claudin 18.2-positive metastatic gastric cancer on zolbetuximab + CAPOX

Robert diagnosed with T3N1 gastric adenocarcinoma 2024, underwent perioperative FLOT + subtotal gastrectomy. Surveillance CT January 2026 showed new liver lesions and peritoneal nodules. Biopsy: recurrent gastric adenocarcinoma, HER2-negative, claudin 18.2 IHC 3+. Started zolbetuximab + CAPOX.

SSDI application filed February 2026. Listings 13.16B (recurrent) and 13.16C (metastatic) met. CAL for metastatic gastric cancer. Approved 10 days at Ohio DDS. Severe nausea/vomiting requiring aggressive premedication and dose adjustments. Partial response at 3 months.

What to file with your application

1. EGD report with tumor location, length, appearance, biopsy sites
2. Pathology report with histologic type, Lauren classification for gastric, differentiation grade
3. Biomarker testing: HER2 IHC/FISH, PD-L1 CPS, claudin 18.2, MSI/MMR, EBV
4. Cross-sectional imaging (CT chest/abdomen/pelvis with contrast)
5. PET-CT for staging
6. Endoscopic ultrasound for T staging if applicable
7. Peritoneal cytology and staging laparoscopy findings for gastric cancer
8. Weight loss documentation over the preceding 6-12 months
9. Nutritional assessment (albumin, prealbumin, BMI trajectory)
10. Oncology consultation notes with stage and treatment plan
11. Post-operative pathology if surgery performed

Related reading

Full section walkthrough: Section 13.00 cancer basics. Other cancer listings: 13.18 colorectal, 13.19 liver, 13.20 pancreatic.

Frequently asked questions

Next steps

If you were diagnosed with esophageal or gastric cancer, file for SSDI as soon as pathology confirms diagnosis. Metastatic disease has CAL fast-track. Even resectable disease usually meets 13.16 due to the combination of extensive treatment (perioperative chemo, radiation, major surgery) and post-surgical residuals.