Table 6. [Diffuse Gastric and Lobular Breast Cancer Syndrome: Treatment of Manifestations]. - GeneReviews®

Manifestation/Concern	Treatment	Considerations/Other
Diffuse gastric cancer (DGC)	Standard treatment to eradicate H pylori infection
In those w/early DGC: Total gastrectomy involves D-2 dissection, Roux-en-Y esophagojejunostomy, & obtaining proximal margins to ensure removal of gastric mucosa. ¹
In those w/advanced DGC: Total gastrectomy w/perioperative &/or adjuvant therapy (e.g., radiation, chemotherapy) as recommended by multidisciplinary team w/experience in DGC
In children/adolescents w/DGC: If early gastric lesions (pT1a) are identified on surveillance, chemotherapy & radiation therapy are not recommended. In such instances, intensive surveillance should be performed, & interval between endoscopy w/multiple biopsies may decrease from 12 to 6 mos, until total gastrectomy is feasible at full physical maturity. ²	Chemotherapy & radiotherapy are only recommended in children & adolescents if advanced disease is diagnosed or found during surveillance.
An intrauterine device or alternative form of contraception that does not require gastrointestinal absorption is recommended in women who have undergone total gastrectomy.
Lobular breast cancer (LBC)	Treatment includes surgery, hormonal therapy, & perioperative &/or adjuvant chemotherapy depending on LBC stage, overall individual health, tumor aggressiveness, & predictive biomarkers for targeted therapies. Mastectomy is the preferred treatment. The timing for breast reconstruction should be discussed.	The extent of LBC lesions will impact treatment recommendations. LBC staging requires clinical imaging, exam before treatment, tumor pathology, & lymph node analysis. The most common classification systems are the American Joint Commission on Cancer & the International Union for Cancer Control. ³
Risk-reducing contralateral mastectomy may be considered. Chemoprevention can be considered (e.g., selective estrogen receptor modulators or aromatase inhibitors), but due to the significant side effects, long-term applicability is limited. ⁴	In those w/germline CDH1 pathogenic variant & family or personal history of breast cancer
Cleft lip/palate ⁵	Standard treatments for cleft correction by craniofacial specialists	Requires multidisciplinary team, incl craniofacial surgeons, otolaryngologists, geneticists, anesthesiologists, speech-language pathologists, nutritionists, orthodontists, prosthodontists, & psychologists ⁶

Manifestation/Concern

Treatment

Considerations/Other

Diffuse gastric cancer (DGC)

Standard treatment to eradicate H pylori infection

In those w/early DGC:
Total gastrectomy involves D-2 dissection, Roux-en-Y esophagojejunostomy, & obtaining proximal margins to ensure removal of gastric mucosa. ¹

In those w/advanced DGC:
Total gastrectomy w/perioperative &/or adjuvant therapy (e.g., radiation, chemotherapy) as recommended by multidisciplinary team w/experience in DGC

In children/adolescents w/DGC:
If early gastric lesions (pT1a) are identified on surveillance, chemotherapy & radiation therapy are not recommended. In such instances, intensive surveillance should be performed, & interval between endoscopy w/multiple biopsies may decrease from 12 to 6 mos, until total gastrectomy is feasible at full physical maturity. ²

Chemotherapy & radiotherapy are only recommended in children & adolescents if advanced disease is diagnosed or found during surveillance.

An intrauterine device or alternative form of contraception that does not require gastrointestinal absorption is recommended in women who have undergone total gastrectomy.

Lobular breast cancer (LBC)

Treatment includes surgery, hormonal therapy, & perioperative &/or adjuvant chemotherapy depending on LBC stage, overall individual health, tumor aggressiveness, & predictive biomarkers for targeted therapies.
Mastectomy is the preferred treatment. The timing for breast reconstruction should be discussed.

The extent of LBC lesions will impact treatment recommendations. LBC staging requires clinical imaging, exam before treatment, tumor pathology, & lymph node analysis. The most common classification systems are the American Joint Commission on Cancer & the International Union for Cancer Control. ³

Risk-reducing contralateral mastectomy may be considered.
Chemoprevention can be considered (e.g., selective estrogen receptor modulators or aromatase inhibitors), but due to the significant side effects, long-term applicability is limited. ⁴

In those w/germline CDH1 pathogenic variant & family or personal history of breast cancer

Cleft lip/palate ⁵

Standard treatments for cleft correction by craniofacial specialists

Requires multidisciplinary team, incl craniofacial surgeons, otolaryngologists, geneticists, anesthesiologists, speech-language pathologists, nutritionists, orthodontists, prosthodontists, & psychologists ⁶

From: Diffuse Gastric and Lobular Breast Cancer Syndrome

GeneReviews^® [Internet].

Adam MP, Feldman J, Mirzaa GM, et al., editors.

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