Superficially spreading cancer of the stomach

PGE2 promotes breast cancer-associated lymphangiogenesis by activation of EP4 receptor on lymphatic endothelial cells

Background

Lymphatic metastasis, facilitated by lymphangiogenesis is a common occurrence in breast cancer, the molecular mechanisms remaining incompletely understood. We had earlier shown that cyclooxygenase (COX)-2 expression by human or murine breast cancer cells promoted lymphangiogenesis and lymphatic metastasis by upregulating VEGF-C/D production by tumor cells or tumor-associated macrophages primarily due to activation of the prostaglandin receptor EP4 by endogenous PGE2. It is not clear whether tumor or host-derived PGE2 has any direct effect on lymphangiogenesis, and if so, whether EP4 receptors on lymphatic endothelial cells (LEC) play any role.

Methods

Here, we address these questions employing in vitro studies with a COX-2-expressing and VEGF-C/D-producing murine breast cancer cell line C3L5 and a rat mesenteric (RM) LEC line and in vivo studies in nude mice.

Results

RMLEC responded to PGE2, an EP4 agonist PGE1OH, or C3L5 cell-conditioned media (C3L5-CM) by increased proliferation, migration and accelerated tube formation on growth factor reduced Matrigel. Native tube formation by RMLEC on Matrigel was abrogated in the presence of a selective COX-2 inhibitor or an EP4 antagonist. Addition of PGE2 or EP4 agonist, or C3L5-CM individually in the presence of COX-2 inhibitor, or EP4 antagonist, restored tube formation, reinforcing the role of EP4 on RMLEC in tubulogenesis. These results were partially duplicated with a human dermal LEC (HMVEC-dLyAd) and a COX-2 expressing human breast cancer cell line MDA-MB-231. Knocking down EP4 with shRNA in RMLEC abrogated their tube forming capacity on Matrigel in the absence or presence of PGE2, EP4 agonist, or C3L5-CM. RMLEC tubulogenesis following EP4 activation by agonist treatment was dependent on PI3K/Akt and Erk signaling pathways and VEGFR-3 stimulation. Finally in a directed in vivo lymphangiogenesis assay (DIVLA) we demonstrated the lymphangiogenic as well as angiogenic capacity of PGE2 and EP4 agonist in vivo.

Discussion/conclusions

These results demonstrate the roles of tumor as well as host-derived PGE2 in inducing lymphangiogenesis, at least in part, by activating EP4 and VEGFR-3 on LEC. EP4 being a common target on both tumor and host cells contributing to tumor-associated lymphangiogenesis reaffirms the therapeutic value of EP4 antagonists in the intervention of lymphatic metastasis in breast cancer.

Long-term outcomes and survival after laparoscopy-assisted distal gastrectomy for gastric cancer: three-year survival analysis of a single-center experience in Korea

BACKGROUND AND OBJECTIVES

Laparoscopy-assisted distal gastrectomy (LADG) has been established as an alternative treatment for early gastric cancer (EGC) because of excellent short-term results. However, only a few reports have considered the long-term outcomes of LADG. In this study, we investigated the 3-year outcome and survival of patients who underwent LADG.

METHODS

We assessed 182 patients with gastric adenocarcinoma who underwent LADG. The indication for LADG was confined to EGCs (T1N0 or T1N1 cases). The clinicopathological characteristics and long-term survival data of all patients were analyzed.

RESULTS

The overall morbidity and mortality rates of the patients were 11% and 0%, respectively. An analysis of the final pathological stages of the patients revealed that 160 had stage Ia, 20 had stage Ib, and only 2 had stage II. The median follow-up period was 44 months (range, 2-73 months), and there were two recurrences. Five patients died of other causes, but no patients died of a gastric cancer recurrence. The 3-year overall and disease-specific survival rates were 97.3% and 100%, respectively.

CONCLUSIONS

LADG for EGC is acceptable in terms of both short- and long-term outcomes. Thus, LADG can be considered a primary treatment for EGC.

A novel insight of sentinel lymph node concept based on 1-3 positive nodes in patients with pT1-2 gastric cancer

Background

Sentinel node (SN) biopsy has been practiced in gastric cancer in recent years, and many studies focused on the distribution of solitary lymph node metastasis (SLM) to assess the pattern of SN. In fact, there is usually more than one SN existing in gastric cancer. The distribution of SNs needs to be further re-evaluated.

Methods

A total of 289 patients in pT1-2 stage with 1-3 positive nodes confined to same compartment were included in this study with informed consents. The primary lesion was solitary (≤ 5.0 cm in diameter) and D2 or D3 lymph node dissection had been performed. The location of metastatic lymph nodes was analyzed retrospectively.

Results

Most positive nodes occurred in N1 compartment, with frequency of 79.6% to 85.7% based on site of tumor. In the lower third of stomach, no. 6 was the most common metastatic site and no. 3 was the second; the order was reversed for SLM. With increasing depth of tumor invasion, a progressively augmented nodal involvement was shown. Nearly a half appeared transverse metastasis when the tumor located at the lesser or greater curvature. Among skip metastasis, no. 7, 8a, 9 and 11p were the most common metastatic sites and the prognosis was as similar as that of patients with N1 involved only.

Conclusions

The 1-3 positive nodes in the same compartment should be possible SNs, and most of which are restricted in N1 in pT1-2 gastric cancer. Transversal and 2 stations lymph node metastasis are common.

Long-term oncologic outcomes from laparoscopic gastrectomy for gastric cancer: a single-center experience of 601 consecutive resections

BACKGROUND

Laparoscopic gastrectomy (LG) is becoming increasingly popular for management of early gastric cancer (EGC). Although short-term efficacy is proven, reports on long-term effectiveness are still infrequent.

STUDY DESIGN

All patients with a diagnosis of gastric cancer undergoing LG from the beginning of our laparoscopic experience were included in the analysis. At our unit, LG is indicated for all cancers up to preoperative stage T2N1.

RESULTS

Six-hundred and one laparoscopic resections were included in the analysis. There were 392 men and 209 women. Mean age was 64.2 +/- 10.9 years. Distal gastrectomy was performed in 305 patients, pylorus-preserving gastrectomy in 148, segmental gastrectomy in 42, proximal gastrectomy in 53, total gastrectomy in 27, and wedge resection in 26. Histological staging revealed that 478 patients had stage IA disease, 47 had stage IB, 44 had stage IIA, 19 had stage IIB, 8 had stage IIIA, 3 had stage IIIB, and 2 had stage IIIC. Morbidity and mortality rates were 17.6% and 0.3%, respectively. Median follow-up was 35.9 months (range 3 to 113 months). Cancer recurrence occurred in 15 patients and metachronous gastric remnant cancer was detected in 6 patients. The 5-year overall and disease-free survival rates were 94.2% and 89.9%, respectively, for stage IA tumors, 87.4% and 82.7% for stage IB, 80.8% and 70.7% for stage IIA, and 69.6% and 63.1% for stage IIB.

CONCLUSIONS

In our experience, long-term oncological outcomes from LG for EGC are acceptable. Wherever expertise permits, LG should be considered as the primary treatment in patients with EGC.

Partial cancerous changes eventually developing into superficial spreading cancer over 18 months

In this report, we describe a patient presenting with the superficial spreading type of early gastric cancer (egc) accompanied by cancerous ulcers. Disease progression and treatment outcome are discussed. After symptoms persisted for more than 1 year, the patient underwent total gastrectomy with D2 lymph node dissection. The patient was diagnosed with superficial spreading cancer (ssc), accompanied by an extensive iic lesions. The progression of this patient suggests that the co-occurrence of cancerous ulcers may contribute to egc development to some extent. As is known, egc often develops into advanced gastric cancer with time. However, in our case, we observed a process during which partial cancerous changes developed into ssc over 18 months. Superficial spreading cancer should be considered an egc variant, which may have the ability to spread superficially along the stomach wall without invading the muscularis propria. But we speculate that, if gene expression changes for some reason, the malignant ssc cells may acquire the ability to grow deeply into the stomach wall. Eventually, Borrmann type iv gastric cancer may develop.

Lymph node metastasis in submucosal gastric cancer and reduction surgery

Although the concept of early gastric cancer (EGC) has been accepted, lymph node metastasis is the most important prognostic factor for EGC. Submucosal gastric cancer is greatly concerned because of its high lymph node metastasis incidence accounting for about 20% of all lymph node metastases. Many researchers suggest that reduction surgery should be performed for submucosal gastric cancer patients at a lower risk of developing lymph node metastasis. Submucosal gastric cancer can be divided into 3 levels (Sm1, Sm2, Sm3) based on its depth of invasion, which has been proven useful for predicting lymph node metastasis, directing treatment and evaluating prognosis. Recently, with the advances in clinical pathology and molecular biology, the risk factor for lymph node metastasis of submucosal gastric cancer can be accurately evaluated and its treatment has become rather rational. This paper reviews the relative factors for lymph node metastasis of submucosal gastric cancer and advances in its rational surgical treatment.