Peritoneal washing cytology: prognostic value of positive findings in patients with gastric carcinoma undergoing a potentially curative resection

Is there a role for treatment-oriented surgery in liver metastases from gastric cancer?

BACKGROUND

Distant metastases are found in approximately 35% of patients with gastric cancer at their first clinical observation, and of these, 4%-14% involves the liver. Unfortunately, only 0.4%-2.3% of patients with metastatic gastric cancer are eligible for radical surgery. Although surgical resection for gastric cancer metastases is still debated, there have been changes in recent years, although several clinical issues remain to be defined and that must be taken into account before surgery is proposed.

AIM

To analyze the clinicopathological factors related to primary gastric tumor and metastases that impact the survival of patients with liver metastatic gastric cancer.

METHODS

We performed a systematic review of the literature from 2000 to 2018 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The study protocol was based on identifying studies with clearly defined purpose, eligibility criteria, methodological analysis, and patient outcome.

RESULTS

We selected 47 studies pertaining to the purpose of the review, which involved a total of 2304 patients. Median survival was 7-52.3 mo, median disease-free survival was 4.7-18 mo. The 1-, 2-, 3-, and 5-year overall survival (OS) was 33%-90.1%, 10%-60%, 6%-70.4%, and 0%-40.1%, respectively. Only five papers reported the 10-year OS, which was 5.5%–31.5%. The general recurrence rate was between 55.5% and 96%, and that for hepatic recurrence was between 15% and 94%.

CONCLUSION

Serous infiltration and lymph node involvement of the primary cancer indicate an unfavorable prognosis, while the presence of single metastasis or ≤ 3 metastases associated with a size of < 5 cm may be considered data that do not contraindicate liver resection.

Lymph node, peritoneal and bone marrow micrometastases in gastric cancer: Their clinical significance

The 7th TNM classification clearly states that micrometastases detected by morphological techniques (HE stain and immunohistochemistry) should always be reported and calculated in the staging of the disease (pN1mi or M1), while patients in whom micrometastases are detected by non-morphological techniques (e.g., flow cytometry, reverse-transcriptase polymerase chain reaction) should still be classified as N0 or M0. In gastric cancer patients, micrometastases have been detected in lymph nodes, the peritoneal cavity and bone marrow. However, the clinical implications and/or their prognostic significance are still a matter of debate. Current literature suggests that lymph node micrometastases should be encountered for the loco-regional staging of the disease, while skip lymph node micrometastases should also be encountered in the total number of infiltrated lymph nodes. Peritoneal fluid cytology examination should be obligatorily performed in pT3 or pT4 tumors. A positive cytology classifies gastric cancer patients as stage IV. Although a curative resection is not precluded, these patients face an overall dismal prognosis. Whether patients with a positive cytology should be treated similarly to patients with macroscopic peritoneal recurrence should be evaluated further. Gastric cancer cells are detected with high incidence in the bone marrow. However, the published results make comparison of data between groups almost impossible due to severe methodological problems. If these methodological problems are overcome in the future, specific target therapies may be designed for specific groups of patients.