No clear effect of postoperative radiotherapy on survival of breast cancer patients with one to three positive nodes: a population-based study.

BACKGROUND: In published radiotherapy trials, the failure rate in the control arm among patients with one to three positive nodes is high compared with that seen with modern adjuvant treatments. Therefore, the generalizability of the results has been questioned. The aim of the present study was to compare relative survival in breast cancer patients between two Swedish regions with screening mammography programs and adjuvant treatment guidelines similar with the exception of the indication of radiotherapy for patients with one to three positive nodes. PATIENTS AND METHODS: Between 1989 and 2006, breast cancer patients were managed very similarly in the west and southeast regions, except for indication for postoperative radiotherapy. In patients with one to three positive nodes, postmastectomy radiotherapy was generally given in the southeast region (89% of all cases) and generally not given in the west region (15% of all cases). For patients with one to three positive nodes who underwent breast-conserving surgery, patients in the west region had breast radiotherapy only, while patients in the southeast region had both breast and lymph nodes irradiated. RESULTS: The 10-year relative survival for patients with one to three positive lymph nodes was 78% in the west region and 77% in the southeast region (P = 0.12). Separate analyses depending on type of surgery, as well as number of examined nodes, also revealed similar relative survival. CONCLUSION: Locoregional postoperative radiotherapy has well-known side-effects, but in this population-based study, there was little or no influence of this type of radiotherapy on survival when one to three lymph nodes were involved.

Oestrogen receptor co-activator AIB1 is a marker of tamoxifen benefit in postmenopausal breast cancer.

BACKGROUND: The oestrogen receptor (ER) co-activator amplified in breast cancer 1 (AIB1) has been suggested as a treatment predictive and prognostic marker in breast cancer. Studies have however not been unanimous. PATIENTS AND METHODS: AIB1 protein expression was analysed by immunohistochemistry on tissue micro-arrays with tumour samples from 910 postmenopausal women randomised to tamoxifen treatment or no adjuvant treatment. Associations between AIB1 expression, clinical outcome in the two arms and other clinicopathological variables were examined. RESULTS: In patients with ER-positive breast cancer expressing low tumour levels of AIB1 (<75%), we found no significant difference in recurrence-free survival (RFS) or breast cancer-specific survival (BCS) between tamoxifen treated and untreated patients. In patients with high AIB1 expression (>75%), there was a significant decrease in recurrence rate (HR 0.40, 95% CI 0.26-0.61, P < 0.001) and breast cancer mortality rate (HR 0.38, 95% CI 0.21-0.69, P = 0.0015) with tamoxifen treatment. In the untreated arm, we found high expression of AIB1 to be significantly associated with lower RFS (HR 1.74, 95% CI 1.20-2.53, P = 0.0038). CONCLUSION: Our results suggest that high AIB1 is a predictive marker of good response to tamoxifen treatment in postmenopausal women and a prognostic marker of decreased RFS in systemically untreated patients.

Overall survival benefit for sequential doxorubicin-docetaxel compared with concurrent doxorubicin and docetaxel in node-positive breast cancer--8-year results of the Breast International Group 02-98 phase III trial.

Background In women with node-positive breast cancer, the Breast International Group (BIG) 02-98 tested the incorporation of docetaxel (Taxotere) into doxorubicin (Adriamycin)-based chemotherapy, and compared sequential and concurrent docetaxel. At 5 years, there was a trend for improved disease-free survival (DFS) with docetaxel. We present results at 8-year median follow-up and exploratory analyses within biologically defined subtypes. Methods Patients were randomly assigned to one of four treatments: (i) sequential control: doxorubicin (A) (75 mg/m(2)) × 4 →classical cyclophosphamide, methotrexate, 5-fluorouracil (CMF); (ii) concurrent control: doxorubicin, cyclophosphamide (AC)(60/600 mg/m(2)) × 4 →CMF; (iii) sequential docetaxel: A (75 mg/m(2)) × 3 → docetaxel (T) (100 mg/m(2)) × 3 → CMF and (iv) concurrent docetaxel: AT(50/75 mg/m(2)) × 4 →CMF. The primary comparison evaluated docetaxel efficacy regardless of the schedule. Exploratory analyses were undertaken within biologically defined subtypes. Results Two thousand eight hundred and eighty-seven patients were enrolled. After 93.4 months of median follow-up, there were 916 DFS events. For the primary comparison, there was no significant improvement in DFS from docetaxel [hazard ratio (HR) = 0.91, 95% confidence interval (CI) = 0.80-1.05, P = 0.187]. In secondary comparisons, sequential docetaxel significantly improved DFS compared with sequential control (HR = 0.81, 95% CI = 0.67-0.99, P = 0.036), and significantly improved DFS (HR = 0.84, 95% CI = 0.72-0.99, P = 0.035) and overall survival (OS) (HR = 0.79, 95% CI = 0.65-0.98, P = 0.028) compared with concurrent doxorubicin-docetaxel. Luminal-A disease had the best prognosis. HRs favored addition of sequential docetaxel in all subtypes, except luminal-A; but this observation was not statistically supported because of limited numbers. Conclusion With further follow-up, the sequential docetaxel schedule resulted in significantly better OS than concurrent doxorubicin-docetaxel, and continued to show better DFS than sequential doxorubicin-based control.

Time dependent effects of adjuvant tamoxifen therapy on cerebrovascular disease: results from a randomised trial.

BACKGROUND: Tamoxifen has been associated with an increased risk of stroke. There is, however, little information on the effect in the post-treatment period. Using data from the Swedish Breast Cancer Group adjuvant trial of 5 vs 2 years of tamoxifen treatment, we now report both short-term and long-term effects on morbidity as well as mortality because of cerebrovascular disease. METHODS: Data from the Swedish National Hospital Discharge Registry combined with information from the Swedish Cause of Death Registry was used to define events of disease. Hazard ratios (HRs) were estimated using Cox regression. RESULTS: Comparing patients randomised to 5 years of tamoxifen with patients randomised to 2 years of tamoxifen, the incidence of cerebrovascular diseases was increased (HR 1.70, 95% CI 1.05-2.75) during the active treatment phase and reduced after the active treatment period (HR 0.78, 95% CI 0.63-0.96), and the difference in HR between the two time-periods was significant (P=0.0033). The mortality from cerebrovascular diseases was increased during the treatment period (HR 3.18, 95% CI 1.03-9.87) and decreased during the post-treatment period (HR 0.60, 95% CI 0.40-0.90) with a significant difference in HR between the two periods of follow-up (P=0.0066). Similar results were seen for subgroups of cerebrovascular diseases, such as stroke and ischaemic stroke. CONCLUSION: In an adjuvant setting, tamoxifen was associated with an increased risk of cerebrovascular disease during treatment, but a decreased risk in the post-treatment period.

Prognostic utility of HOXB13:IL17BR and molecular grade index in early-stage breast cancer patients from the Stockholm trial.

BACKGROUND: A dichotomous index combining two gene expression assays, HOXB13:IL17BR (H:I) and molecular grade index (MGI), was developed to assess risk of recurrence in breast cancer patients. The study objective was to demonstrate the prognostic utility of the combined index in early-stage breast cancer. METHODS: In a blinded retrospective analysis of 588 ER-positive tamoxifen-treated and untreated breast cancer patients from the randomised prospective Stockholm trial, H:I and MGI were measured using real-time RT-PCR. Association with patient outcome was evaluated by Kaplan-Meier analysis and Cox proportional hazard regression. A continuous risk index was developed using Cox modelling. RESULTS: The dichotomous H:I+MGI was significantly associated with distant recurrence and breast cancer death. The >50% of tamoxifen-treated patients categorised as low-risk had <3% 10-year distant recurrence risk. A continuous risk model (Breast Cancer Index (BCI)) was developed with the tamoxifen-treated group and the prognostic performance tested in the untreated group was 53% of patients categorised as low risk with an 8.3% 10-year distant recurrence risk. CONCLUSION: Retrospective analysis of this randomised, prospective trial cohort validated the prognostic utility of H:I+MGI and was used to develop and test a continuous risk model that enables prediction of distant recurrence risk at the patient level.

Survival patterns of invasive lobular and invasive ductal breast cancer in a large population-based cohort with two decades of follow up.

BACKGROUND: Invasive lobular carcinoma (ILC) comprises 8-15 % of all invasive breast cancers and large population-based studies with >10 years of follow-up are rare. Whether ILC has a long-time prognosis different from that of invasive ductal carcinoma, (IDC) remains controversial. PURPOSE: To investigate the excess mortality rate ratio (EMRR) of patients with ILC and IDC and to correlate survival with clinical parameters in a large population-based cohort. MATERIAL AND METHODS: From 1989 through 2006, we identified 17,481 patients diagnosed with IDC (n = 14,583) or ILC (n = 2898), younger than 76 years from two Swedish Regional Cancer Registries. Relative survival (RS) during 20 years of follow up was analysed. RESULTS: ILC was significantly associated with older age, larger tumours, ER positivity and well differentiated tumours. We noticed an improved survival for patients with ILC during the first five years, excess mortality rate ratio (EMRR) 0.64 (CI 95 % 0.53-0.77). This was shifted to a significant decreased survival 10-15 years after diagnosis (EMRR 1.49, CI 95 % 1.16-1.93). After 20 years the relative survival rates were similar, 0.72 for ILC and 0.73 for IDC. CONCLUSIONS: During the first five years after surgery, the EMRR was lower for patients with ILC as compared to patients with IDC, but during the years 10-15 after surgery, we observed an increased EMRR for patients with ILC as compared to IDC. These EMRR between ILC and IDC were statistically significant but the absolute difference in excess mortality between the two groups was small.

Hypoxia, Snail and incomplete epithelial-mesenchymal transition in breast cancer.

BACKGROUND: Hypoxia is an element of the tumour microenvironment that impacts upon numerous cellular factors linked to clinical aggressiveness in cancer. One such factor, Snail, a master regulator of the epithelial-mesenchymal transition (EMT), has been implicated in key tumour biological processes such as invasion and metastasis. In this study we set out to investigate regulation of EMT in hypoxia, and the importance of Snail in cell migration and clinical outcome in breast cancer. METHODS: Four breast cancer cell lines were exposed to 0.1% oxygen and expression of EMT markers was monitored. The migratory ability was analysed following Snail overexpression and silencing. Snail expression was assessed in 500 tumour samples from premenopausal breast cancer patients, randomised to either 2 years of tamoxifen or no adjuvant treatment. RESULTS: Exposure to 0.1% oxygen resulted in elevated levels of Snail protein, along with changes in vimentin and E-cadherin expression, and in addition increased migration of MDA-MB-468 cells. Overexpression of Snail increased the motility of MCF-7, T-47D and MDA-MB-231 cells, whereas silencing of the protein resulted in decreased migratory propensity of MCF-7, MDA-MB-468 and MDA-MB-231 cells. Moreover, nuclear Snail expression was associated with tumours of higher grade and proliferation rate, but not with disease recurrence. Interestingly, Snail negativity was associated with impaired tamoxifen response (P=0.048). CONCLUSIONS: Our results demonstrate that hypoxia induces Snail expression but generally not a migratory phenotype, suggesting that hypoxic cells are only partially pushed towards EMT. Furthermore, our study supports the link between Snail and clinically relevant features and treatment response.

Effects of adjuvant tamoxifen over three decades on breast cancer-free and distant recurrence-free interval among premenopausal women with oestrogen receptor-positive breast cancer randomised in the Swedish SBII:2pre trial.

AIMS: The primary aim was to compare 2 years of adjuvant tamoxifen versus no systemic treatment in premenopausal patients with oestrogen receptor (ER)-positive tumours, regarding breast cancer-free interval (BCFi) and distant recurrence-free interval (D-RFi), with 30 years of follow-up and for specified intervals. Moreover, we aimed to investigate the effects of adjuvant tamoxifen on the incidence of secondary malignancies and survival after distant recurrence. METHODS: Premenopausal patients with primary breast cancer were randomised to 2 years of tamoxifen (n = 277) or no systemic treatment (n = 287), irrespective of ER status. Information regarding events was collected by a review of medical records and from national registers. RESULTS: The median follow-up for all patients without events was 28 years, and only four of the patients alive had a follow-up of <20 years. With 30 years of follow-up, tamoxifen prolonged BCFi in the intention-to-treat population (hazard ratio [HR] = 0.76, 95% confidence interval (CI) 0.61-0.94, p = 0.011) compared with no treatment. In patients with ER-positive tumours (n = 362), tamoxifen prolonged BCFi (HR = 0.62, 95% CI 0.47-0.82, p = 0.001) and D-RFi (HR = 0.73, 95% CI 0.54-0.99, p = 0.043). The positive effect on BCFi was significant also for the interval >15-30 years (HR = 0.53, 95% CI 0.28-0.98, p = 0.042). For patients with ER-positive tumours who were diagnosed with distant recurrence (n = 165), survival after distant recurrence was shorter among tamoxifen-treated patients (median, 29 months versus 43 months). The incidence of contralateral breast cancer was 42% lower in the tamoxifen group (HR = 0.58, 95% CI 0.35-0.96, p = 0.035), whereas no differences were observed regarding other secondary malignancies. CONCLUSIONS: With three decades of follow-up, 2 years of adjuvant tamoxifen reduced the incidence of breast cancer-related events and distant recurrence, and the carryover effect seems to extend beyond 15 years. Moreover, adjuvant tamoxifen seems to be associated with shorter survival after diagnosis of distant recurrence.

Amplification of CCND1 and PAK1 as predictors of recurrence and tamoxifen resistance in postmenopausal breast cancer.

The 11q13 region is amplified in approximately 15% of all breast tumors. Situated in this region are the cyclin D1 gene (CCND1) and the p-21-activated kinase 1 (PAK1) gene. Both genes encode proteins shown to activate the estrogen receptor (ER), leading to transcription of CCND1 and other ER-responsive genes. Here, we investigate the prognostic and treatment predictive role of CCND1 and PAK1 gene amplification in postmenopausal breast cancer patients randomized to tamoxifen treatment or no adjuvant treatment. Amplification of CCND1 and PAK1, assessed by real-time PCR, was observed in 12.5 and 9.3%, respectively. Amplification of PAK1 was seen in 37% of the CCND1-amplified tumors, indicating coamplification (P<0.001). In ER-positive patients, amplification of at least one of the genes indicated a reduced recurrence-free survival (P=0.025). When response to tamoxifen treatment was analysed, patients with PAK1 amplification showed decreased benefit from the drug (ER+; relative risk ratio (RR)=1.62; 95% confidence interval (CI), 0.47-5.55) compared to patients without amplification (ER+; RR=0.53; 95% CI, 0.32-0.88). This was not evident for CCND1 amplification. We show that PAK1 may be a predictor of tamoxifen resistance and furthermore, we do not discard PAK1 as a potential candidate oncogene in the 11q13 amplicon. In addition, we show that high pak1 protein levels may predict tamoxifen insensitivity.

Is risk of central nervous system (CNS) relapse related to adjuvant taxane treatment in node-positive breast cancer? Results of the CNS substudy in the intergroup Phase III BIG 02-98 Trial.

BACKGROUND: Breast cancer central nervous system (CNS) metastases are an increasingly important problem because of high CNS relapse rates in patients treated with trastuzumab and/or taxanes. PATIENTS AND METHODS: We evaluated data from 2887 node-positive breast cancer patients randomised in the BIG 02-98 trial comparing anthracycline-based adjuvant chemotherapy (control arms) to anthracycline-docetaxel-based sequential or concurrent chemotherapy (experimental arms). After a median follow-up of 5 years, 403 patients had died and detailed information on CNS relapse was collected for these patients. RESULTS: CNS relapse occurred in 4.0% of control patients and 3.7% of docetaxel-treated patients. CNS relapse occurred in 27% of deceased patients in both treatment groups. CNS relapse was usually accompanied by neurologic symptoms (90%), and 25% of patients with CNS relapse died without evidence of extra-CNS relapse. Only 20% of patients survived 1 year from the diagnosis of CNS relapse. Prognosis of CNS relapse was worse for patients with meningeal carcinomatosis when compared with brain metastases. Unexpected findings included a higher rate of positive cerebrospinal fluid cytology (8% versus 3%) and more frequent use of magnetic resonance imaging for diagnosis (47% versus 30%) in the docetaxel-treated patients. CONCLUSION: There is no evidence that adjuvant docetaxel treatment is associated with an increased frequency of CNS relapse.

Adjuvant goserelin in pre-menopausal patients with early breast cancer: Results from the ZIPP study.

The Zoladex In Pre-menopausal Patients (ZIPP) study was designed to determine whether addition of goserelin ('Zoladex') and/or tamoxifen to adjuvant therapy (radiotherapy and/or chemotherapy), provided benefit to pre- or peri-menopausal women with operable, early breast cancer. A combined analysis of four randomised trials using a core protocol was performed. Patients (n = 2710) were randomised into a 2 x 2 factorial trial based on goserelin and tamoxifen (n = 1800) or randomised to receive goserelin or not (n = 910; some received elective tamoxifen) for 2 years. The analysis presented here compares women who did (n = 1354) or did not (n = 1356) receive goserelin. After a median follow-up of 5.5 years, goserelin provided a significant benefit for event-free survival (hazard ratio [HR] 0.80; 95% confidence interval [CI] 0.69, 0.92; P = 0.002) and overall survival (HR 0.81; 95% CI 0.67, 0.99; P = 0.038). Goserelin was well tolerated. These data show that the addition of goserelin to standard adjuvant therapy is more effective than standard therapy alone in pre-menopausal women with early breast cancer.

Estradiol receptor analysis in human breast cancer tissue by isoelectric focusing in polyacrylamide gel.

Isoelectric focusing in polyacrylamide gel combined with limited proteolysis is a simple and specific method for quantitation of estradiol receptors in breast cancer tissue. At least eight different samples can be analyzed simultaneously on one gel, and the whole procedure, including sample preparation, takes less than 7 hr. In comparison with sucrose gradient centrifugation, isoelectric focusing is more sensitive, possibly due to the short time (1.5 to 2 hr) needed for the analysis. Furthermore, only one incubation with tritium-labeled estradiol is needed for an analysis, which means that a smaller amount of tumor tissue is needed than for most other methods. This fact allows analysis of the estrogen receptor content in tumor material obtained from fine-needle biopsy.

A novel p53 germline alteration identified in a late onset breast cancer kindred.

Germline mutations in the p53 tumor suppressor gene are associated with the Li-Fraumeni syndrome, characterized by childhood sarcoma, leukemia and early onset breast cancer and has occasionally been found also in familial breast-ovarian cancer. Most mutations found are of missense type and located in the central region of the gene (exons 5 to 8). In the present study, a germline p53 alteration was identified in a late onset breast cancer family (kindred Lund 5; mean age 58 years) using single stranded conformation polymorphism and sequence analysis. The mutation (a CCG to CTG transition) at codon 82 in exon 4, resulting in a proline to leucine substitution, has not previously been reported and was not present in a control set of 60 healthy individuals. Three of five woman with breast cancer (45, 57 and 65 years) were carriers of the alteration. Loss of heterozygosity at the p53 locus was not seen in the primary tumors of these women, but appeared as a partial loss of the wildtype allele in subsequent recurrent lesions of two gene carriers. The family manifested no linkage to the p53 gene (a two-point LOD-score of -0.41), and has previously also been excluded for linkage to the BRCA1 and BRCA2 loci, as well as being carrier of a BRCA1 germline mutation. Although it seems unlikely that the p53 germline mutation is the major cause of disease predisposition in Lund 5, the data suggest that some p53 alteration may confer a subtle influence on breast cancer development and progression.

Expression of the deleted in colorectal cancer gene is related to prognosis in DNA diploid and low proliferative colorectal adenocarcinoma.

PURPOSE: Whether or not the deleted in colorectal cancer (DCC) gene is implicated in metastases or in predicting prognosis in patients with colorectal cancer has not previously been substantiated. Our aims were to investigate DCC expression in primary colorectal cancers and in metastases to identify any prognostic significance. PATIENTS AND METHODS: DCC expression was examined immunohistochemically in 195 primary colorectal adenocarcinomas and in 23 paired primary tumors and lymph node metastases. DNA content and S-phase fraction were measured by flow cytometry. RESULTS: The absence of DCC expression was observed in 55 primary tumors (28%). DCC negativity was significantly related to poor prognosis in patients with DNA diploid tumors (P =.03) and those with a low S-phase fraction (< 5%, P =.02) but not in patients with nondiploid tumors or those with a higher S-phase fraction. Furthermore, DCC expression retained its prognostic significance in the diploid subgroup after adjusting for sex, age, site, stage, growth pattern, and differentiation (P =.01). DCC expression was similar in primary tumors and their metastases. CONCLUSION: The absence of DCC predicted a poor outcome in the patients with diploid tumors and those tumors with a low S-phase fraction. Immunohistochemistry may be considered as a practical test to assess prognosis in this subgroup of patients.

S-phase fraction is a prognostic factor in stage I breast carcinoma.

PURPOSE AND METHODS: The prognostic significance of cell proliferation, estimated as cytometric S-phase fraction (SPF), was investigated in node-negative breast cancer patients with small tumors (T1, NO). The 219 stage I patients originated from two series and were diagnosed either from 1978 to 1981 or from 1981 to 1985. The tumors were analyzed for estrogen receptors (ERs) by isoelectric focusing and for cellular DNA content by static cytofluorometry or flow cytometry. RESULTS: A high SPF correlated with the absence of ERs and abnormal DNA content, and was less often found in tumors smaller than 11 mm compared with those with a diameter between 11 and 20 mm. Among the variables age, tumor size, DNA ploidy, ER status, and SPF, only SPF showed a significant association with distant recurrence and breast cancer survival in systemically untreated patients. The relative recurrence rate for patients with an SPF of 10% or greater was three times that for patients with lower SPFs. Estimated 8-year breast cancer survival rates for the same groups were 72% and 91%, respectively. CONCLUSION: This study suggests that cytometric SPF has prognostic significance in stage I breast carcinoma.

The relationship between hormone receptor content and the effect of adjuvant tamoxifen in operable breast cancer.

The relationship between hormone receptor status and the effect of adjuvant tamoxifen in early breast cancer remains controversial. This article presents the results of a randomized trial of adjuvant tamoxifen (40 mg daily for 2 years) versus no adjuvant endocrine therapy in postmenopausal patients. During 1976 to 1984, 1,407 patients were included in the study. Of these, 427 (30%) had high-risk tumors (pN + or pT greater than 30 mm) and were included in a concurrent randomized comparison of postoperative radiotherapy versus adjuvant polychemotherapy. The mean follow-up time was 61/2 years. Tamoxifen improved the recurrence-free survival (RFS) (P less than .01), but the overall survival difference in favor of the tamoxifen-allocated patients was not significant. Data on estrogen (ER) and progesterone receptor (PgR) content were available in 750 patients. Their mean follow-up time was 41/2 years. The effect of tamoxifen was significantly related to ER level (P less than .01). No benefit with tamoxifen was observed among ER-negative patients. The relation to PgR level was of borderline significance (P = .06). Multivariate analysis indicated that most of the interaction between treatment and receptor content was explained by the interaction with ER (P less than .01). The PgR status appeared to modify the effect of tamoxifen among the ER-positive patients and the greatest effect was observed among patients who were positive for both receptors. However, the additional predictive information provided by the PgR assay did not help to identify an unresponsive subgroup of patients.

Pathology parameters and adjuvant tamoxifen response in a randomised premenopausal breast cancer trial.

BACKGROUND: Subgroups of breast cancer that have an impaired response to endocrine treatment, despite hormone receptor positivity, are still poorly defined. Breast cancer can be subdivided according to standard pathological parameters including histological type, grade, and assessment of proliferation. These parameters are the net result of combinations of genetic alterations effecting tumour behaviour and could potentially reflect subtypes that respond differently to endocrine treatment. AIMS: To investigate the usefulness of these parameters as predictors of the response to tamoxifen in premenopausal women with breast cancer. MATERIALS/METHODS: Clinically established pathological parameters were assessed and related to the tamoxifen response in 500 available tumour specimens from 564 premenopausal patients with breast cancer randomised to either two years of tamoxifen or no treatment with 14 years of follow up. Proliferation was further evaluated by immunohistochemical Ki-67 expression. RESULTS: Oestrogen receptor positive ductal carcinomas responded as expected to tamoxifen, whereas the difference in recurrence free survival between control and tamoxifen treated patients was less apparent in the relatively few lobular carcinomas. For histological grade, there was no obvious difference in treatment response between the groups. The relation between proliferation and tamoxifen response seemed to be more complex, with a clear response in tumours with high and low proliferation, whereas tumours with intermediate proliferation defined by Ki-67 responded more poorly. CONCLUSIONS: Clinically established pathology parameters seem to mirror the endocrine treatment response and could potentially be valuable in future treatment decisions for patients with breast cancer.

K-ras mutations in colorectal adenocarcinomas and neighbouring transitional mucosa.

The K-ras gene in codons 12 and 13 was investigated using allele-specific polymerase chain reaction in matched normal mucosa (n = 106), transitional mucosa (n = 69) and tumours (n = 149) from 149 patients with colorectal adenocarcinomas. K-ras mutations in codon 12 were detected in 41/149 (28%) of tumours and 4/69 (6%) of transitional mucosa samples, but not in the normal mucosa. Further, mutation rates were increased in younger patients (P = 0.001) and in mucinous carcinomas (50%) compared with well differentiated (17%), moderately differentiated (26%) or poorly differentiated (24%) tumours. Our findings indicate that mucinous carcinoma may represent a distinct genetic entity.

c-erbB-2 expression and benefit from adjuvant chemotherapy and radiotherapy of breast cancer.

Frozen tissue from primary tumours of 152 premenopausal breast cancer patients, who participated in a trial comparing radiotherapy with adjuvant chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil, CMF), was analysed for c-erbB-2 protein expression, measured by flow cytometry. The relative risk of distant recurrence or death in the chemotherapy group as compared with the radiotherapy group was 3.0 (95% confidence interval (CI) 1.1-7.8) for patients whose tumours showed high c-erbB-2 levels and 0.87 (95% CI 0.43-1.7) for those with tumours with low levels of c-erbB-2 protein. Patients with highly proliferative tumours that did not overexpress c-erbB-2 benefited most, in terms of survival, from CMF. In addition, we found an increased risk of locoregional recurrence for tumours overexpressing c-erbB-2 when radiotherapy was replaced by chemotherapy.

Cellular accumulation of p53 protein: an independent prognostic factor in stage II breast cancer.

The p53 gene product is a tumour suppressor protein, and alterations of the protein are common in human cancer. Previous studies have focused on nuclear accumulation of p53. To investigate if cytoplasmic accumulation of p53 strengthens the relationships to different pathobiological variables and distant recurrence-free survival in breast cancer, tumours from 164 stage II patients were examined with the monoclonal antibody PAb1801. Nine per cent of the tumours were nuclear positive and 21% were cytoplasmic positive. Cellular p53 accumulation, related to the nucleus or the cytoplasm or both, showed stronger associations with pathobiological variables than nuclear accumulation alone. Accumulation of p53 was significantly correlated to tumour size over 20 mm, negative oestrogen receptor (ER) status, DNA aneuploidy, high S-phase fraction and positive erbB-2 status. Cytoplasmic p53 was significantly correlated to distance recurrence-free survival in patients negative for nuclear p53 (P < 0.0001). Cellular p53 accumulation was an independent prognostic factor, in addition to lymph node status and ER content. We conclude that consideration of cytoplasmic staining enhances the clinical importance of p53.