Biological resonance for cancer metastasis, a new hypothesis based on comparisons between primary cancers and metastases

Expression and prognostic value of epithelial-to-mesenchymal transition and cancer stem cellmarkersin primary lesions and liver metastases of colorectal cancers

Cancer stem cells (CSCs) and epithelial mesenchymal transition (EMT) markers are considered useful indicators associated with metastasis and prognosis of colorectal cancers (CRCs). However, only a few studies have focused on the expression of these useful markers in metastases. Metastasectomy is widely used in advanced CRCs, and thus the postoperative prognostic factors are worth investigating. The present study investigated the consistency and differences of target proteins between primary and metastatic lesions of colorectal cancer, and discussed the prognostic indicators following resection of colorectal liver metastases. Clinical data of 56 patients with liver metastases from colorectal cancer were collected and the expression levels of target proteins (Ki-67, CD133, CD44, Snail, E-cadherin and β-catenin) were detected in primary tumor and matched liver metastases via immunohistochemistry analysis. Paired comparison between both tissue types was performed. The prognostic values of the target proteins for resectable colorectal cancer liver metastases were assessed. No significant differences were observed between the primary tissues and metastatic tissues. The consistency rates of these protein expression levels ranged from 51.8-78.6%. The maximum diameter of the liver metastases was <5 cm. Low Snail expression in metastases was associated with a longer overall survival (OS) time following resection of colorectal liver metastases. Furthermore, N0 stage and low carcinoembryonic antigen levels were associated with a longer progression-free survival time. Notably, no significant differences were observed in expression levels of the target proteins between the primary tumors and liver metastases. Taken together, the results of the present study suggest that Snail expression in liver metastases may be used as a novel independent prognostic factor for OS following resection of colorectal liver metastases.

SLC39A4 expression is associated with enhanced cell migration, cisplatin resistance, and poor survival in non-small cell lung cancer

The zinc transporter SLC39A4 influences epithelial cell morphology and migration in various cancers; however, its role in regulating cell invasion and chemotherapeutic resistance in human lung cancer is not yet clear. Here, integrated analysis of gene expression in non-small cell lung cancer revealed that SLC39A4 expression is significantly correlated with increased tumour size and regional lymph node spread, as well as shorter overall survival (OS) and disease-free survival (DFS). SLC39A4 silencing by lentivirus-mediated shRNA blocked human lung cancer cell epithelial-mesenchymal transition and metastasis in vitro and in vivo, respectively. Moreover, SLC39A4 knockdown enhanced cancer cell sensitivity to cisplatin-induced death by inhibiting stemness in lung cancer cells. Collectively, these data suggest that SLC39A4 may be a novel therapeutic target and predictive marker of tumour metastasis in non-small cell lung cancer.

Survival of breast cancer patients according to changes in expression of selected markers between primary tumor and lymph node metastases

BACKGROUND

The differences between primary and metastatic tumor cells might be important for treatment selection and prognostication.

MATERIALS & METHODS

Expression of ER, PR, HER2, CK5/6, EGFR, Ki-67, Ep-CAM, P-cadherin, CD24, CD44, ALDH was assessed immunohistochemically in primary tumor (T) and corresponding synchronous nodal metastases (LNM) in 156 invasive ductal breast cancer patients (T ≥1, N ≥1, M0).

RESULTS

Independent negative prognostic factors for disease-free survival were pN3, ALDH immunopositivity in LNM, nonluminal A subtype in LNM, reduction of Ep-CAM expression in LNM, lack of changes or enhancement of CK5/6 and ALDH expression in LNM.

DISCUSSION

Our results suggest that in some cases expression of markers in lymph node metastases might bring additional prognostic information to that obtained from primary tumor.

Durable recurrence-free survival after pneumonectomy for late lung metastasis from rectal cancer: case report with genetic and epigenetic analyses

BACKGROUND

Treatment of pulmonary recurrence from colorectal cancer involving the main bronchus usually entails palliation using interventional bronchoscopy, because the prognosis is generally very poor. Surgical experience has clarified that in this setting pneumonectomy should only be performed in carefully selected patients showing favorable prognostic profiles (defined by low carcinoembryonic antigen serum levels pre-thoracotomy), solitary and completely resectable pulmonary metastasis, and long disease-free intervals. In the few long-term survivors after pneumonectomy for late-recurrent colorectal cancer, the disease has a relatively indolent metastatic course and genetic and epigenetic profiling may provide further insight regarding tumor evolution.

CASE PRESENTATION

We describe a rare case of late hilar-endobronchial and lymph nodal recurrence of rectal cancer, sequential to hepatic metastasectomy, that we successfully treated with pneumonectomy and chemotherapy (leucovorin, 5-fluorouracil and oxaliplatin regimen); the patient achieved 7-year relapse-free survival after lung metastasectomy and 24-year overall survival after primary rectal cancer resection. To our knowledge, this is the longest survival reported after sequential liver resection and pneumonectomy for recurrent colorectal cancer. In our case the primary rectal cancer and its recurrences showed identical immunohistochemical patterns. The primary rectal cancer and the matched metastases (hepatic, pulmonary and lymph nodal) demonstrated no KRAS, NRAS, BRAF and PIK3CA mutations, a microsatellite stable phenotype, and no tumor protein p53 alterations or recurrent copy number alterations on chromosome 8. High genetic concordances between the paired primary tumor and metastases suggest that the key tumor biological traits remained relatively conserved in the three metastatic sites. Minor differences in gene specific hypermethylation were observed between the primary tumor and lung and nodal metastases. These differences suggest that epigenetic mechanisms may be causally involved in the microenvironmental regulation of cancer metastasis.

CONCLUSION

The exceptionally long survival of the patient in our case study involving favorable clinical features was related to an excellent response to surgery and adjuvant chemotherapy; however, genetic or epigenetic factors that remain unidentified cannot be excluded as contributory factors. Our findings support the concept of a common clonal origin of the primary cancer and synchronous and late metastases, and suggest that aberrant DNA methylation may regulate tumor dormancy mechanisms.