Loss of 4q21.23-22.1 Is a Prognostic Marker for Disease Free and Overall Survival in Non-Small Cell Lung Cancer

Abstract

This study was performed to assess the prognostic relevance of genomic aberrations at chromosome 4q in NSCLC patients. We have previously identified copy number changes at 4q12-q32 to be significantly associated with the early hematogenous dissemination of non-small cell lung cancer (NSCLC), and now aim to narrow down potential hot-spots within this 107 Mb spanning region. Using eight microsatellite markers at position 4q12-35, allelic imbalance (AI) analyses were performed on a preliminary study cohort (n = 86). Positions indicating clinicopathological and prognostic associations in AI analyses were further validated in a larger study cohort using fluorescence in situ hybridization (FISH) in 209 NSCLC patients. Losses at positions 4q21.23 and 4q22.1 were shown to be associated with advanced clinicopathological characteristics as well as with shortened disease free (DFS) and overall survival (OS) (DFS: P = 0.019; OS: P = 0.002). Multivariate analyses identified the losses of 4q21.23-22.1 to be an independent prognostic marker for both DFS and OS in NSCLC (HR 1.64–2.20, all P<0.04), and especially in squamous cell lung cancer (P<0.05). A case report study of a lung cancer patient further revealed a loss of 4q21.23 in disseminated tumor cells (DTCs). Neither gains at the latter positions, nor genomic aberrations at 4q12, 4q31.2 and 4q35.1, indicated a prognostic relevance. In conclusion, our data indicate that loss at 4q21.23-22.1 in NSCLC is of prognostic relevance in NSCLC patients and thus, includes potential new tumor suppressor genes with clinical relevance.

Identification of HERC5 and its potential role in NSCLC progression

“…Supporting the assumption that HERC5 could be used as a prognostic marker, methylation at cg08750951, using a cut‐off β ‐value of 0.4 (40% methylation) predicts 5 year survival of Stage I ADC patients in a separate independent patient group. Interestingly HERC5 is located within the narrow hot spot region identified in our recent study, which found loss of 4q21.2–22.1 to be an independent poor prognostic factor in NSCLC . These results strongly suggest that HERC5 may be involved in the tumor dissemination of NSCLC and may qualify as a negative prognostic factor.…”

“…Furthermore, allelic imbalance analyses and FISH studies identified the core region 4q21.2–22.1, which was significantly associated with worse prognosis. In addition, the same loss could be identified in single DTCs, pinpointing the importance of this region in metastasis …”

“…For the methylation array analyses three different lung cancer cell lines were chosen that reflect the situation in the primary tumors, that is, showing a one‐allele loss of 4q. Validation of 4q21 loss was done by FISH using the probe already used in our previous studies …”

“…The high risk of relapse even among early‐stage lung cancer patients has been linked to the presence of DTCs in the BM at the time of operation . We have previously shown that the existence of these single tumor cells in the BM is associated with a specific genetic profile with loss of 4q significantly associated with the DTC status of a patient and that loss of 4q21–22 is an independent negative prognostic factor in NSCLC . However, in contrast to breast cancer where numerous large studies and meta‐analyses have shown a clear correlation between DTC status and prognosis, in lung cancer the link with DTC status is controversially discussed …”

HERC5 is a prognostic biomarker for post-liver transplant recurrent human hepatocellular carcinoma

“…This region accounts for ~107 Mbp in length and similar deletions have been associated with either poor prognosis or advanced disease stages in pancreatic, colorectal, non-small cell lung cancer (NSCLC), and HCC tumors [ 42 – 46 ]. Within NSCLC specifically, FISH assays identified the primary region of 4q21.2-22.1 to be associated with poor prognosis [ 44 , 46 , 47 ], and a recent study from this same group showed that hypermethylation of HERC5 promoter (located at 4q22.1), and thus under-expression of the gene correlated with: positive disseminated tumor cells in the bone marrow, brain metastasis, and poor survival in both stage I adenocarcinoma and metastatic lung cancer patients [ 46 ]. Our results presented here in primary tumors of HCC patients are in agreement with these reports, underscoring the prognostic significance of HERC5 under-expression, as we have demonstrated with microarray or RNASeq technologies in primary tumors of three independent cohorts of HCC patients.…”