Differential effect of adjuvant taxane-based and taxane-free chemotherapy regimens on the CK-19 mRNA-positive circulating tumour cells in patients with early breast cancer.

BACKGROUND: To determine the effect of adjuvant taxane-free and taxane-based chemotherapy regimens on the elimination of circulating tumour cells (CTCs) in patients with early breast cancer. METHODS: The presence of CK-19 mRNA-positive CTCs in the peripheral blood was evaluated before and after chemotherapy, using a real-time RT-PCR assay, in a historical comparison of two cohorts of women with stage I-III breast cancer treated with adjuvant taxane-free (N=211; FE(75)C or E(75)C) and taxane-based (N=334; T/E(75)C or T/E(75)) chemotherapy. RESULTS: Taxane-based chemotherapy resulted in a higher incidence of CTCs' elimination than taxane-free regimens since 49.7% (74 of 149) and 33.0% (29 of 88) of patients with detectable CTCs before chemotherapy, respectively, turned negative post-chemotherapy (P=0.015). Patients treated with taxane-free regimens had a significantly lower disease-free survival (DFS) (P=0.035) than patients treated with taxane-based regimens; this difference was observed in patients with but not without detectable CTCs before chemotherapy (P=0.018 and P=0.481, respectively). The incidence of deaths was significantly higher in the taxane-free cohort of patients with but not without detectable CTCs before chemotherapy compared with that of the taxane-based cohort (P=0.002). Multivariate analysis revealed that the chemotherapy regimen was significantly associated with prolonged DFS (HR: 2.00; 95% CI=1.20-3.34). CONCLUSION: Elimination of CK-19 mRNA-positive CTCs during adjuvant chemotherapy seems to be an efficacy indicator of treatment and is associated with a favourable clinical outcome of patients with detectable CTCs before chemotherapy.

Prognostic significance of SOX17 and WNT5a promoter methylation status in circulating cell-free DNA metastatic colorectal cancer patients.

Aim: Carcinogenesis of colorectal cancer is a process involving genetic mutations and epigenetic alterations in its multiple phases. The most considerable epigenetic alteration occurring in colorectal cancer (CRC) tumorigenesis is the methylation-mediated silencing of tumor suppressor genes. The present study aimed to detect the methylation status of SOX17 and WNT5a promoters in cell-free DNA circulating in plasma of metastatic CRC patients and to investigate potential prognostic correlation. Methods: A methylation-specific real-time polymerase chain reaction was utilized to investigate the methylation status of genes (SOX17 and WNT5a) promoter in the blood of 85 metastatic CRC patients. Results: We found the SOX17 promoter methylated in 54/85 (63.5 %) while WNT5a was methylated in 39/85 (45.8 %) samples of the advanced CRC. All control samples were negative for SOX17 and WNT5a promoter methylation. Patients with metastatic CRC and methylated SOX17 and WNT5a promoter status had a significantly poorer outcome than patients with non-methylated ones. Conclusions: Plasma SOX17 and WNT5a promoter methylation are frequent epigenetic events in advanced CRC. The reported correlations between the methylation status of genes (SOX17 and Wnt5a) promoter and poorer survival in patients with advanced CRC disease agree with the proposed role of SOX17 as a tumor suppressor gene. A more considerable CRC patient cohort is required to research these findings' potential further and investigate whether SOX17 in plasma could serve as a useful prognostic biomarker in metastatic CRC. HIPPOKRATIA 2023, 27 (1):7-11.

Docetaxel plus oxaliplatin in combination with capecitabine as first-line treatment for advanced gastric cancer.

OBJECTIVE: In the present phase II study, we evaluated the efficacy and safety of a docetaxel-oxaliplatin-capecitabine combination as a first-line treatment in patients with advanced gastric cancer. PATIENTS AND METHODS: A total of 27 patients (18 males) with histologically confirmed inoperable gastric adenocarcinoma were recruited. Docetaxel was given (50 mg/m(2) i.v.) on day 1 followed by oxaliplatin (75 mg/m(2) i.v.) also on day 1. Capecitabine (2,750 mg/m(2)) was given orally as two daily divided doses from days 1 to 7. Cycles were repeated every 2 weeks. All patients had measurable disease and 18 of them had a performance status (WHO) of 0. RESULTS: A total of 240 treatment cycles were administered. All patients were evaluable for toxicity. Four patients who discontinued treatment early (having received only 3 chemotherapy cycles) were included as non-responders in an intention-to-treat response analysis. Complete response, partial response, stable disease and progressive disease were observed in 4 (15%), 12 (44%), 3 (11%) and 8 (30%) patients, respectively. The observed response rate was 59%, and the disease control rate (complete response + partial response + stable disease) was 70%. At the time of analysis, 6 patients were still alive and the median survival was 18.0 months. The most common grade III/IV toxicities observed were neutropenia (5%), diarrhea (2%), palmar-plantar erythrodysesthesia (2%) and neurotoxicity (1%). All other toxicities were mostly of grade I/II and easily manageable. CONCLUSION: The combination of docetaxel, oxaliplatin and capecitabine in the described mode of administration represents a relatively active and well-tolerated regimen in patients with advanced gastric cancer and warrants further evaluation.

Biweekly vinorelbine and gemcitabine as second-line treatment and beyond in non-small cell lung cancer.

BACKGROUND: To evaluate the activity and tolerance of gemcitabine (GEM) in combination with vinorelbine (VRL) in pretreated patients with advanced non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: Fifteen patients with advanced NSCLC who had disease progression after a cisplatin- or taxane-based front-line regimen were enrolled into a 2-stage design trial and were treated with VRL 30 mg/m² i.v. for 10 min followed by GEM 1,200 mg/m² i.v. for 30 min on days 1 and 15 of each 28-day cycle. Chemotherapy was given for 6 cycles unless disease progression or unacceptable toxicity was seen. The patients' median age was 64 years and the performance status (WHO) was 0 (n = 7), 1 (n = 5), and 2 (n = 3). The treatment was second line for 10 (67%) and third line or more for 5 (33%) patients. RESULTS: No complete or partial responses were observed. Stable disease was seen in 4 (27%) patients and progressive disease in 11 (73%). The median time to tumor progression was 3 months (range 1-12) and the median survival was 4 months (range 2-31). Severe myelotoxicity was infrequent. Grade 2 neutropenia was observed in 2 (13%) patients, grade 2 thrombocytopenia in 1 (7%), and grade 2 anemia in 3 (20%). Nonhematologic toxicities were very mild and easily manageable. CONCLUSION: The GEM plus VRL combination at the present doses and schedule is a safe but ineffective regimen; therefore, it is not recommended as second-line treatment in patients with advanced NSCLC.

Detection of cytokeratin-19 mRNA-positive cells in the peripheral blood and bone marrow of patients with operable breast cancer.

BACKGROUND: To compare detection rates and evaluate the clinical relevance of cytokeratin-19 (CK-19) mRNA-positive cells in the peripheral blood (circulating tumour cells, CTCs) and bone marrow (disseminated tumour cells; DTCs) of patients with early breast cancer. METHODS: Paired samples of peripheral blood and bone marrow were obtained from 165 patients with stage I-II breast cancer before the initiation of adjuvant chemotherapy. In 84 patients, paired blood and bone marrow samples were also available after chemotherapy. The detection of CK-19 mRNA-positive CTCs and DTCs was assessed by real-time PCR. RESULTS: CK-19 mRNA-positive CTCs and DTCs were detected in 55.2 and 57.6% of patients before chemotherapy, respectively. After chemotherapy, CTCs and DTCs were identified in 44 (52.4%) and 43 (51.2%) of the 84 patients, respectively. There was a 93.9% (McNemar; P=0.344) and 72.6% (McNemar; P=0.999) concordance between blood and bone marrow samples before and after chemotherapy, respectively. The detection of CK-19 mRNA-positive CTCs or DTCs before chemotherapy was associated with decreased overall survival (P=0.024 and P=0.015, respectively). In addition, their simultaneous detection was also associated with an increased incidence of disease-related death and decreased overall survival (P=0.016). CONCLUSIONS: The detection of CK-19 mRNA-positive CTCs using reverse transcription-PCR (RT-PCR) both before and after chemotherapy is correlated with the detection of CK-19 mRNA-positive DTCs in patients with early-stage breast cancer. The determination of the CTC status by RT-PCR conveys clinically relevant information that is not inferior to DTC status and, owing to the ease of sampling, warrants further evaluation as a tool for monitoring minimal residual disease.

Clinical relevance of circulating CK-19 mRNA-positive cells detected during the adjuvant tamoxifen treatment in patients with early breast cancer.

BACKGROUND: The purpose of this study was to evaluate the effect of adjuvant treatment with tamoxifen on the CK-19 mRNA+ cells in patients with early-stage breast cancer. PATIENTS AND METHODS: CK-19 mRNA+ cells were prospectively and longitudinally detected using a specific real-time PCR assay for CK-19 mRNA in 119 patients with estrogen and/or progesterone receptor-positive tumors during the period of tamoxifen administration. RESULTS: Twenty-two (18.5%) patients had detectable CK-19 mRNA+ cells after the completion of adjuvant chemotherapy and in 15 (68.2%) of them adjuvant tamoxifen could not eliminate these cells (persistently positive). In 68 (57.1%) patients, no CK-19 mRNA+ cells could be detected throughout the follow-up period (persistently negative). Seven (46.7%) of the 15 persistently positive and six (8.8%) of the 68 persistently negative patients developed disease recurrence (P = 0.00026). Persistency of CK-19 mRNA+ cells was associated with a significantly lower median disease-free interval (P = 0.0001) and overall survival (P = 0.0005). Multivariate analysis revealed that the detection of CK-19 mRNA+ cells during the administration of tamoxifen was associated with an increased risk of relapse [hazard ratio (HR) = 22.318, P = 0.00006] and death (HR = 13.954, P < 0.00001). CONCLUSIONS: The detection of CK-19 mRNA+ cells throughout the period of adjuvant tamoxifen treatment is an independent poor prognostic factor in patients with early breast cancer.

Molecular detection of cytokeratin-19-positive cells in the peripheral blood of patients with operable breast cancer: evaluation of their prognostic significance.

PURPOSE: To evaluate the prognostic significance of molecular detection of cytokeratin 19 (CK-19) mRNA-positive cells by nested reverse transcriptase polymerase chain reaction (RT-PCR) in the peripheral blood of women with stages I and II breast cancer before adjuvant chemotherapy. PATIENTS AND METHODS: The sensitivity and specificity of CK-19 mRNA detection by nested RT-PCR were investigated using MCF-7 and ARH-77 cells and blood from healthy women and patients with hematologic malignancies, metastatic colorectal cancer, and early and metastatic breast cancer. Peripheral blood from 148 patients with operable breast cancer, obtained before initiation of any adjuvant therapy, was tested for the presence of CK-19 mRNA-positive cells. RESULTS: The nested RT-PCR assay for CK-19 mRNA detected one MCF-7 tumor cell in 10(6) normal peripheral blood mononuclear cells in four of five experiments; no signal was detected with the CK-19-negative ARH-77 cells. CK-19 mRNA was detected in the peripheral blood of 3.7% of healthy blood donors, 14.3% of patients with hematologic malignancies, and 3.2% of patients with metastatic colorectal cancer. Detection rates for CK-19 mRNA-positive cells in the bone marrow/blood of patients with early or metastatic breast cancer were 63%/30% and 74%/52%, respectively. For stages I and II breast cancer, detection of CK-19-positive cells in the peripheral blood before adjuvant therapy was associated with reduced disease-free interval (P =.0007) and overall survival (P =.01). In multivariate analysis, detection of peripheral-blood CK-19-positive cells was an independent prognostic factor for disease relapse and death. CONCLUSION: Molecular detection of CK-19 mRNA-positive cells by RT-PCR in the peripheral blood of patients with stages I and II breast cancer before initiation of adjuvant therapy has independent prognostic value as a marker of poor clinical outcome.

Prognostic role of APC and RASSF1A promoter methylation status in cell free circulating DNA of operable gastric cancer patients.

Gastric carcinogenesis is a multistep process including not only genetic mutations but also epigenetic alterations. The best known and more frequent epigenetic alteration is DNA methylation affecting tumor suppressor genes that may be involved in various carcinogenetic pathways. The aim of the present study was to investigate the methylation status of APC promoter 1A and RASSF1A promoter in cell free DNA of operable gastric cancer patients. Using methylation specific PCR, we examined the methylation status of APC promoter 1A and RASSF1A promoter in 73 blood samples obtained from patients with gastric cancer. APC and RASSF1A promoters were found to be methylated in 61 (83.6%) and 50 (68.5%) of the 73 gastric cancer samples examined, but in none of the healthy control samples (p < 0.001). A significant association between methylated RASSF1A promoter status and lymph node positivity was observed (p = 0.005). Additionally, a significant correlation between a methylated APC promoter and elevated CEA (p = 0.033) as well as CA-19.9 (p = 0.032) levels, was noticed. The Kaplan-Meier estimates of survival, significantly favored patients with a non-methylated APC promoter status (p = 0.008). No other significant correlations between APC and RASSF1A methylation status and different tumor variables examined was observed. Serum RASSF1A and APC promoter hypermethylation is a frequent epigenetic event in patients with early operable gastric cancer. The observed correlations between APC promoter methylation status and survival as well as between a hypermethylated RASSF1A promoter and nodal positivity may be indicative of a prognostic role for those genes in early operable gastric cancer. Additional studies, in a larger cohort of patients are required to further explore whether these findings could serve as potential molecular biomarkers of survival and/or response to specific treatments.

A multicenter phase I-II study of docetaxel plus epirubicin plus bevacizumab as first-line treatment in women with HER2-negative metastatic breast cancer.

PURPOSE: To assess the efficacy and toxicity of docetaxel (D) plus epirubicin (E) in combination with bevacizumab (B) [DEB regimen] as front-line treatment in patients with metastatic breast cancer (MBC). PATIENTS AND METHODS: Women with previously untreated HER2-negative MBC received B (15 mg/kg), E (75 mg/m2) and D (75 mg/m2) with prophylactic G-CSF support every 3 weeks (q3w) for up to 9 cycles followed by B (15 mg/kg q3w) until disease progression. Primary endpoint was the overall response rate (ORR). Circulating tumor cells (CTCs) were evaluated using the CellSearch system at different time points during therapy. RESULTS: Eighty-three women were enrolled with median age 62 years, performance status 0-1 in 93%, triple negative disease in 12% and liver metastases in 47%. In an intention to treat analysis, complete response was achieved in 13 (15.7%) and partial response in 42 (50.6%) (overall response rate 66.3%; 95% CI 56.09-76.44%). The median time to progression was 20.1 months and the 1-year overall survival rate 82.3%. Grade 3-4 neutropenia occurred in 37%, febrile neutropenia in 10%, anemia in 4%, thrombocytopenia in 2% and diarrhea in 2% of patients. There were two deaths possibly related to study treatment (sigmoid perforation n = 1; sudden death n = 1). Moreover, one patient developed pulmonary embolism and another one myocardial infarction while on treatment. Although DEB administration significantly reduced the proportion of patients presenting CTCs, the detection of ≥5 or ≥1 CTCs before treatment initiation was significantly associated with worse progression-free survival (p = 0.001 and p = 0.004) and overall survival (p = 0.001 and p = 0.027), respectively. CONCLUSIONS: The DEB regimen is a very active but also potentially toxic combination in MBC. Detection of CTCs before treatment is associated with worse outcome. CLINICALTRIALSGOV: NCT00705315.

Docetaxel plus gemcitabine in combination with capecitabine as treatment for inoperable pancreatic cancer: a phase II study.

PURPOSE: To evaluate the activity and tolerance of gemcitabine in combination with docetaxel and capecitabine in previously untreated patients with advanced pancreatic cancer. PATIENTS AND METHODS: Chemotherapy-naïve patients with locally advanced or metastatic pancreatic cancer were treated with gemcitabine (1,500 mg/m(2) on days 1 and 15), docetaxel (50 mg/m(2) on days 1 and 15) and capecitabine (2,250 mg/m(2), orally in two daily divided doses, on days 1-7 and 15-21). All three drugs were administered in 4-week cycles, in an initial prospective plan of six cycles. The primary end-point was response rate. RESULTS: Forty patients were enrolled in the study. At the time of enrollment, 40% of patients had locally advanced and 60% metastatic disease. All patients were evaluable for response and toxicity. On an intent-to-treat analysis, the overall response and disease control rates were 40 and 80%, respectively. The median progression-free survival was 6.0 months, and the median overall survival was 9.0 months. Major grade 3/4 toxicities were neutropenia (17.5%), diarrhea (10%) and hand-foot syndrome (7.5%). There was no treatment-related death. CONCLUSION: The combination of gemcitabine with docetaxel and capecitabine is feasible and exhibits satisfactory degree of activity in patients with advanced pancreatic cancer, deserving further exploration.

Biweekly vinorelbine and gemcitabine as second-line and beyond treatment in ovarian cancer.

PURPOSE: To evaluate the activity and tolerance of vinorelbine (VRL) in combination with gemcitabine (GEM) in pre-treated patients with refractory ovarian cancer. PATIENTS AND METHODS: Seventeen patients with ovarian cancer who had disease progression after a carboplatin and taxane front-line regimen were treated with VRL 30 mg/m(2) IV over 10 min followed by GEM 1,200 mg/m(2) IV over 30 min on days 1 and 15 of each 28 days cycle. Chemotherapy was given in a initial prospective plan of six cycles, unless disease progression or unacceptable toxicity was seen, giving more cycles as consolidation therapy in the case of CR, PR or SD. The median age of patients was 67 years old, and the performance status (WHO) was 1 for 13 and 2 for 4 patients. The treatment was second-line for 11 (65%) and >third-line for 6 (35%) patients. RESULTS: One complete and one partial response were observed (ORR:11%). Stable disease was seen in 4 (24%) patients and progressive disease in 11 (65%). The median time to tumor progression was 4 months (range 2-11), and the median survival has not yet been reached. Myelotoxicity was rare. Grade 1 neutropenia was observed just in one patient and grade 2/3 anemia in four patients (24%). Thrombocytopenia was absent. Non-hematologic toxicity was also predictable and easily manageable. CONCLUSION: The vinorelbine plus gemcitabine combination at the present doses and schedule is a safe but ineffective regimen, and therefore, is not recommended as second-line and beyond treatment in patients with refractory ovarian cancer.

Etoposide plus cisplatin followed by concurrent chemo-radiotherapy and irinotecan plus cisplatin for patients with limited-stage small cell lung cancer: A multicenter phase II study.

PURPOSE: The combination of irinotecan and cisplatin (IP) has shown at least comparable efficacy to that of etoposide/cisplatin (EP) in patients with extensive-stage small cell lung cancer. We conducted a phase II study to evaluate the efficacy and tolerance of EP regimen followed by thoracic radiotherapy (TRT) and IP consolidation chemotherapy in patients with limited-stage small cell lung cancer. PATIENTS AND METHODS: Thirty-three chemotherapy-naive patients with limited-stage small cell lung cancer (LS-SCLC) were treated with etoposide 100mg/m(2) on days 1-3 and cisplatin 80mg/m(2) on day 1. Radiotherapy was given 3 weeks after the first treatment cycle concurrently with weekly cisplatin 20mg/m(2) on day 1 and etoposide 50mg/m(2) on day 4 within 5-6 weeks, followed by three courses of irinotecan 60mg/m(2) on days 1, 8, and 15 and cisplatin 60mg/m(2) on day 1 of a 4-week cycle. RESULTS: There were no treatment-related deaths. Toxicities during chemo-radiotherapy were mild including grade 3/4 neutropenia (24%) and grade 2 esophagitis (6%). The major toxicity observed during consolidation chemotherapy was grades 3-4 neutropenia which affected 42% of patients. In an intention-to-treat analysis the overall response rate was 66% (CR: 30% and PR: 36%). After a median follow-up period of 35.7 months (range: 9.6-41.2 months), the median survival time was 19 months (95% CI: 14.5-23.5 months), the median time to tumor progression 8.3 months and the 1- and 2-year survival rates 72% and 27.5%, respectively. CONCLUSIONS: Consolidation chemotherapy with IP following concurrent EP plus TRT is a safe and with acceptable toxicity regimen and deserves further phase III testing in patients with LS-SCLC.

Sequential gemcitabine and cisplatin followed by docetaxel as first-line treatment of advanced urothelial carcinoma: a multicenter phase II study of the Hellenic Oncology Research Group.

BACKGROUND: The purpose of this study was to investigate the toxicity and efficacy of the sequential administration of gemcitabine (GMB) in combination with cisplatin (CDDP) followed by docetaxel (Taxotere) as first-line treatment of advanced urothelial carcinoma. PATIENTS AND METHODS: Patients [aged

Combination of irinotecan (CPT-11) plus 5-fluorouracil and leucovorin (FOLFIRI regimen) as first line treatment for elderly patients with metastatic colorectal cancer: a phase II trial.

PURPOSE: To evaluate the efficacy and tolerance of irinotecan (CPT-11) in combination with bolus and continuous infusion of 5-fluorouracil (5-FU) and leucovorin (LV) (FOLFIRI regimen) as first-line treatment of elderly patients with metastatic colorectal cancer (MCC). METHODS: Thirty consecutive, previously untreated patients with metastatic colorectal cancer, aged (median 76 years; range 70-84) were enrolled. The performance status (WHO) was 0 in 8, 1 in 16 and 2 in 6 patients; 19 (63%) patients had prior surgery and 8 (27%) adjuvant chemotherapy. CPT-11 (180 mg/m(2) as a 90 min i.v. infusion) was administered on day 1, LV (200 mg/m(2) as a 2-hour i.v. infusion), 5-FU (400 mg/m(2)/d i.v. bolus followed by 600 mg/m(2)/d as a 22-hour i.v. continuous infusion) were given on days 1 and 2 every 2 weeks. RESULTS: Complete response was achieved in one (3.3%) patient and partial response in 10 (33.3%) (overall response rate: 36.6%; 95% C.I.: 26.6-48.4%); 11 (36.6%) patients had stable disease and, 8 (26.6%) disease progression. The median duration of response was 7.5 months and the median time to disease progression 7.0 months. After a median follow-up period of 17 months, the median overall survival was 14.5 months. Main toxicities were: grade 3-4 neutropenia (n = 6; 20%), grade 3 thrombocytopenia (n = 1; 3.3%), grade 2 anemia (n = 9; 30%), grade 3-4 diarrhea (n = 5; 17%) and grade 3 asthenia (n = 3; 10%). There was one treatment-related death due to neutropenic sepsis. CONCLUSIONS: The FOLFIRI combination is an active regimen with manageable toxicity as front-line treatment in patients above 70 years of age.

Dose escalation study on oxaliplatin and capecitabine (Xeloda) in patients with advanced solid tumors.

OBJECTIVES: Capecitabine (CAP) and oxaliplatin (OX) have shown interesting activity in a wide range of solid tumors. A phase I study was conducted in order to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of their combination in patients with refractory solid tumors. PATIENTS AND METHODS: Thirty-three pretreated patients with histologically confirmed inoperable neoplasms were enrolled. The patients' median age was 64 years, 21 were males, and 27 had a WHO performance status of 0-1. OX was administered on days 1 and 8, as a 3-hour intravenous infusion, at escalated doses ranging from 50 to 70 mg/m(2). CAP was administered orally for 14 consecutive days, at escalated doses ranging from 1,200 to 2,100 mg/m(2)/day. Treatment was repeated every 3 weeks. RESULTS: At the dose of 2,100 mg/m(2) (Xeloda) and 70 mg/m(2) (OX), all 3 enrolled patients presented DLT (grade 3 diarrhea, grade 3 asthenia and grade 3 neurotoxicity, respectively), and, thus, the recommended MTD for future phase II studies are 2,000 mg/m(2) for CAP and 70 mg/m(2 )for OX. A total of 145 treatment cycles were administered. Toxicity was very mild. Grade 2/3 neutropenia was observed in 4 (3%) treatment cycles. The main nonhematologic toxicities were grade 2/3 nausea/vomiting (7 cycles; 5%), grade 2/3 neurotoxicity (10 cycles; 7%), grade 2/3 asthenia (8 cycles; 5.5%) and grade 2/3 diarrhea (6 cycles; 4%). There was no treatment-related death. One (4%) complete remission, 2 (8%) partial remissions, and 9 (36%) cases of stable disease were observed among 25 evaluable patients. CONCLUSIONS: The results demonstrate that CAP and OX can be safely combined at clinically relevant doses and that this regimen merits further evaluation.

Peripheral blood circulating cytokeratin-19 mRNA-positive cells after the completion of adjuvant chemotherapy in patients with operable breast cancer.

BACKGROUND: The purpose of this study was to evaluate the prognostic significance of the molecular detection of cytokeratin 19 (CK-19) mRNA-positive cells in the peripheral blood of women with operable breast cancer after the completion of adjuvant chemotherapy. PATIENTS AND METHODS: Blood from 161 patients with stage I and II breast cancer, obtained after the completion of adjuvant chemotherapy, was tested by nested RT-PCR for CK-19 mRNA detection. Using univariate and multivariate analyses possible interactions with other prognostic factors and association of CK-19 mRNA detection with risk of relapse, disease-free interval (DFI) and overall survival were investigated. RESULTS: After completion of adjuvant chemotherapy, 27.3% of patients had peripheral blood CK-19 mRNA-positive cells; there was no association of this finding with any other prognostic factors or the type of chemotherapy regimen used. For patients with less than four involved axillary lymph nodes the risk of relapse was 3.81 [95% confidence interval (CI) 1.06-13.71] times higher, and the DFI was significantly reduced (P = 0.028) if CK-19 mRNA-positive cells were detectable in the blood after the completion of adjuvant chemotherapy. In contrast, for patients with four or more involved lymph nodes, the presence of CK-19 mRNA-positive cells after adjuvant chemotherapy did not significantly affect the risk of relapse or DFI. Furthermore, the risk of relapse was higher (hazards ratio 3.70; 95% CI 1.09-13.89) and the DFI was reduced (P = 0.022) for patients with detectable CK-19 mRNA-positive cells following adjuvant cyclophosphamide, methotrexate and 5-fluorouracil (CMF) as compared with epirubicin, cyclophosphamide and 5-fluorouracil (FEC) or sequential taxotere-epirubicin and cyclophosphamide (T/EC) chemotherapy. CONCLUSIONS: The detection of CK-19 mRNA-positive cells in the peripheral blood after adjuvant chemotherapy may be of clinical relevance for patients with early breast cancer and less than four involved axillary lymph nodes.