Prognostic markers for colorectal cancer: estimating ploidy and stroma.

Background: We report here the prognostic value of ploidy and digital tumour-stromal morphometric analyses using material from 2624 patients with early stage colorectal cancer (CRC). Patients and methods: DNA content (ploidy) and stroma-tumour fraction were estimated using automated digital imaging systems and DNA was extracted from sections of formalin-fixed paraffin-embedded (FFPE) tissue for analysis of microsatellite instability. Samples were available from 1092 patients recruited to the QUASAR 2 trial and two large observational series (Gloucester, n = 954; Oslo University Hospital, n = 578). Resultant biomarkers were analysed for prognostic impact using 5-year cancer-specific survival (CSS) as the clinical end point. Results: Ploidy and stroma-tumour fraction were significantly prognostic in a multivariate model adjusted for age, adjuvant treatment, and pathological T-stage in stage II patients, and the combination of ploidy and stroma-tumour fraction was found to stratify these patients into three clinically useful groups; 5-year CSS 90% versus 83% versus 73% [hazard ratio (HR) = 1.77 (95% confidence interval (95% CI): 1.13-2.77) and HR = 2.95 (95% CI: 1.73-5.03), P < 0.001]. Conclusion: A novel biomarker, combining estimates of ploidy and stroma-tumour fraction, sampled from FFPE tissue, identifies stage II CRC patients with low, intermediate or high risk of CRC disease specific death, and can reliably stratify clinically relevant patient sub-populations with differential risks of tumour recurrence and may support choice of adjuvant therapy for these individuals.

DNA ploidy in curettage specimens identifies high-risk patients and lymph node metastasis in endometrial cancer.

BACKGROUND: Preoperative risk stratification is essential in tailoring endometrial cancer treatment, and biomarkers predicting lymph node metastasis and aggressive disease are aspired in clinical practice. DNA ploidy assessment in hysterectomy specimens is a well-established prognostic marker. DNA ploidy assessment in preoperative curettage specimens is less studied, and in particular in relation to the occurrence of lymph node metastasis. METHODS: Curettage image cytometry DNA ploidy in relation to established clinicopathological variables and outcome was investigated in 785 endometrial carcinoma patients prospectively included in the MoMaTEC multicentre trial. RESULTS: Diploid curettage status was found in 72.0%, whereas 28.0% were non-diploid. Non-diploid status significantly correlated with traditional aggressive postoperative clinicopathological features, and was an independent predictor of lymph node metastasis among FIGO stage I-III patients in multivariate analysis (OR 1.94, P=0.033). Non-diploid status was related to shorter disease-specific survival (5-year DSS of 74.4% vs 88.8% for diploid curettage, P<0.001). When stratifying by FIGO stage and lymph node status, the prognostic effect remained. However, in multivariate regression analysis, preoperative histological risk classification was a stronger predictor of DSS than DNA ploidy. CONCLUSIONS: Non-diploid curettage is significantly associated with aggressive clinicopathological phenotype, lymph node metastasis, and poor survival in endometrial cancer. The prognostic effect was also observed among subgroups with (presumably) less aggressive traits, such as low FIGO stage and negative lymph node status. Our results indicate curettage DNA ploidy as a possible supplement to existing parameters used to tailor surgical treatment.

Prognostic impact of genomic instability in colorectal cancer.

BACKGROUND: The prognostic impact of an indication of chromosomal instability (CIN) is evaluated in a consecutive series of 952 colorectal cancer patients treated at Aker University Hospital, Norway, during 1993-2003. Microsatellite instability (MSI) in this case series has recently been reported and made it possible to find the co-occurrence and compare the prognostic significance of CIN and MSI. METHODS: Data sets for overall survival (OS; n=855) and time to recurrence (TTR; n=579) were studied. To reveal CIN we used automated image cytometry (ICM). Non-diploid histograms were taken as indicative of the presence of CIN. PCR-based measures of MSI in this material have already been described. RESULTS: As with MSI, CIN was found to be an independent predictor of early relapse and death among stage II patients (TTR: n=278: HR 2.19 (95% CI: 1.35-3.55), P=0.002). Of the MSI tumours (16%), 71% were found to be DNA diploid, 21% were DNA tetraploid and 8% were DNA aneuploid. Among microsatellite stable tumours, 24% were DNA diploid, 15% were DNA tetraploid and 61% were DNA aneuploid. CONCLUSION: For patients presenting with stage II disease, genomic instability as detected by DNA image cytometry has the potential to provide a useful biomarker for relapse and cancer-related death following surgery with curative intent.