Under-reporting of subjective symptoms and its prognostic value: a pooled analysis of 12 cancer clinical trials.

BACKGROUND: Oncologists tend to under-report subjective symptoms during cancer treatment. This study describes the under-reporting rate of selected symptoms and explores its association with overall survival (OS). A secondary aim is to test the association of patient-reported symptoms with OS. PATIENTS AND METHODS: This is a post hoc analysis on data pooled from 12 randomized trials, promoted by the National Cancer Institute of Naples (Italy), enrolling patients between 2002 and 2019, with published primary analyses. Occurrence and grade of six side-effects (anorexia, nausea, vomiting, constipation, diarrhea and fatigue) reported by physicians were compared with corresponding symptoms reported by patients in quality-of-life (QoL) questionnaires. Under-reporting was defined as the rate of cases reported grade 0 by the physician while grade ≥1 by the patient. Prognostic value was tested in a multivariable model stratified by trial, including age, sex and performance status as confounders. A landmark threshold was defined for OS analyses. RESULTS: 3792 patients with advanced lung, ovarian, pancreatic, breast or colorectal cancer were pooled; 2603 (68.6%) were eligible having at least one toxicity assessment and one QoL questionnaire, before the first planned disease restaging. Concordance between physicians' and patients' reporting was low with Cohen's k coefficients ranging from 0.03 (fatigue) to 0.33 (vomiting). Under-reporting ranged from 52.7% (nausea) to 80.5% (anorexia), and was not associated with OS. Patient-reported anorexia, vomiting and fatigue ('a little' or more) were significantly associated with shorter OS. CONCLUSIONS: Under-reporting of treatment side-effects is frequent, but it does not affect OS. Patients' reported symptoms should be used for prognostic evaluation.

The association of financial difficulties with clinical outcomes in cancer patients: secondary analysis of 16 academic prospective clinical trials conducted in Italy.

BACKGROUND: Cancer may cause financial difficulties, but its impact in countries with public health systems is unknown. We evaluated the association of financial difficulties with clinical outcomes of cancer patients enrolled in academic clinical trials performed within the Italian public health system. PATIENTS AND METHODS: Data were pooled from 16 prospective multicentre trials in lung, breast or ovarian cancer, using the EORTC quality of life (QOL) C30 questionnaire. Question 28 scores financial difficulties related to disease or treatment in four categories from 'not at all' to 'very much'. We defined financial burden (FB) as any financial difficulty reported at baseline questionnaire, and financial toxicity (FT) as score worsening in a subsequent questionnaire. We investigated (i) the association of FB with clinical outcomes (survival, global QOL response [questions 29/30] and severe toxicity), and (ii) the association of FT with survival. Multivariable analyses were performed using logistic regression models or the Cox model adjusting for trial, gender, age, region and period of enrolment, baseline global QOL and, where appropriate, FB and global QOL response. Results are reported as odds ratio (OR) or hazard ratio (HR) with 95% confidence intervals (CI). RESULTS: At baseline 26% of the 3670 study patients reported FB, significantly correlated with worse baseline global QOL. FB was not associated with risks of death (HR 0.94, 95% CI 0.85-1.04, P = 0.23) and severe toxicity (OR 0.90, 95% CI 0.76-1.06, P = 0.19) but was predictive of a higher chance of worse global QOL response (OR 1.35, 95% CI 1.08-1.70, P = 0.009). During treatment, 2735 (74.5%) patients filled in subsequent questionnaires and 616 (22.5%) developed FT that was significantly associated with an increased risk of death (HR 1.20, 95% CI 1.05-1.37, P = 0.007). Several sensitivity analyses confirmed these findings. CONCLUSION: Even in a public health system, financial difficulties are associated with relevant cancer patients outcomes like QOL and survival. CLINICAL TRIALS NUMBER: Any registered clinical trial number should be indicated after the abstract.

Weekly docetaxel versus CMF as adjuvant chemotherapy for older women with early breast cancer: final results of the randomized phase III ELDA trial.

BACKGROUND: Evidence on adjuvant chemotherapy in older women with breast cancer is poor. We tested whether weekly docetaxel is more effective than standard chemotherapy. PATIENTS AND METHODS: We carried out a multicenter, randomized phase III study. Women aged 65-79, operated for breast cancer, with average to high risk of recurrence, were allocated 1 : 1 to CMF (cyclophosphamide 600 mg/m², methotrexate 40 mg/m², fluorouracil 600 mg/m², days 1, 8) or docetaxel (35 mg/m(2) days 1, 8, 15) every 4 weeks, for four or six cycles according to hormone receptor status. Primary end point was disease-free survival (DFS). A geriatric assessment was carried out. Quality of life (QoL) was assessed with EORTC C-30 and BR-23 questionnaires. RESULTS: From July 2003 to April 2011, 302 patients were randomized and 299 (152 allocated CMF and 147 docetaxel) were eligible. After 70-month median follow-up, 109 DFS events were observed. Unadjusted hazard ratio (HR) of DFS for docetaxel versus CMF was 1.21 [95% confidence interval (CI) 0.83-1.76, P = 0.32]; DFS estimate at 5 years was 0.69 with CMF and 0.65 with docetaxel. HR of death was 1.34 (95% CI 0.80-2.22, P = 0.26). There was no interaction between treatment arms and geriatric scales measuring patients' ability or comorbidities. Hematological toxicity, mucositis and nausea were worse with CMF; allergy, fatigue, hair loss, onychopathy, dysgeusia, diarrhea, abdominal pain, neuropathy, cardiac and skin toxicity were worse with docetaxel. One death was attributed to CMF and two to docetaxel. Increasing age, impairment in instrumental daily living activities, number of comorbidities and docetaxel treatment were independently associated with severe nonhematological toxicity. QoL was worse with docetaxel for nausea-vomiting, appetite loss, diarrhea, body image, future perspective, treatment side-effects and hair loss items. CONCLUSIONS: Weekly docetaxel is not more effective than standard CMF as adjuvant treatment of older women with breast cancer and worsens QoL and toxicity. CLINICALTRIALSGOV: NCT00331097.

The Breast Avastin Trial: phase II study of bevacizumab maintenance therapy after induction chemotherapy with docetaxel and capecitabine for the first-line treatment of patients with locally recurrent or metastatic breast cancer.

BACKGROUND: Therapeutic approach for patients with metastatic breast cancer (MBC) is still controversial. This study was conducted to assess the efficacy and safety of bevacizumab in combination with docetaxel plus capecitabine as first-line treatment for MBC. The feasibility of bevacizumab maintenance therapy in this setting was also evaluated. PATIENTS AND METHODS: In this single-arm, multicenter phase II study, patients received bevacizumab 15 mg/kg and docetaxel 60 mg/m(2) on day 1, plus capecitabine 900 mg/m(2) twice daily on days 1-14 every 21 days. Treatment was administered for up to 6 cycles, then bevacizumab continued until progressive disease. The primary end point was progression-free survival (PFS); secondary end points were tumor response rate, overall survival, and toxicity. RESULTS: Seventy-nine eligible patients were treated with bevacizumab in combination with docetaxel plus capecitabine. The overall response rate was 61 %, with a complete response rate of 8 % and a median duration of response of 10 months. At a median follow-up of 28 months, the median PFS was 11 months. Fifty-two (65 %) patients received bevacizumab maintenance therapy for a median duration of 7 months (range 1 to 33+). Neutropenia was the most common grade 3-4 toxicity (28.1 % of patients), and two fatal adverse events occurred (septic shock and gastrointestinal perforation). CONCLUSIONS: Bevacizumab in combination with docetaxel and capecitabine demonstrates significant activity and quite acceptable toxicity profile as first-line treatment of MBC. Subsequent maintenance therapy with bevacizumab is feasible for a long period of stable disease. Results deserve confirmation.

Bone effect of adjuvant tamoxifen, letrozole or letrozole plus zoledronic acid in early-stage breast cancer: the randomized phase 3 HOBOE study.

BACKGROUND: To measure bone mineral density (BMD) reduction produced by letrozole as compared with tamoxifen and the benefit of the addition of zoledronic acid. PATIENTS AND METHODS: A phase 3 trial comparing tamoxifen, letrozole or letrozole+zoledronic acid in patients with hormone receptor-positive early breast cancer was conducted; triptorelin was given to premenopausal patients. Two comparisons were planned: letrozole versus tamoxifen and letrozole+zoledronic acid versus letrozole. Primary end point was the difference in 1-year change of T-score at lumbar spine (LTS) measured by dual energy X-ray absorptiometry scan. RESULTS: Out of 483 patients enrolled, 459 were available for primary analyses. Median age was 50 (range 28-80). The estimated mean difference (95% confidence interval [CI]) in 1-year change of LTS was equal to -0.30 (95% CI -0.44 to -0.17) in the letrozole versus tamoxifen comparison (P<0.0001) and to +0.60 (95% CI +0.46 to +0.77) in the letrozole+zoledronic acid versus letrozole comparison (P<0.0001). Bone damage by letrozole decreased with increasing baseline body mass index in premenopausal, but not postmenopausal, patients (interaction test P=0.004 and 0.47, respectively). CONCLUSIONS: In the HOBOE (HOrmonal BOne Effects) trial, the positive effect of zoledronic acid on BMD largely counteracts damage produced by letrozole as compared with tamoxifen. Letrozole effect is lower among overweight/obese premenopausal patients.

Is epirubicin effective in first-line chemotherapy of metastatic breast cancer (MBC) after an epirubicin-containing adjuvant treatment? A single centre phase III trial.

The aim of the study was to demonstrate the superiority of docetaxel and epirubicin vs docetaxel alone as first-line therapy in metastatic breast cancer patients pretreated with adjuvant or neoadjuvant epirubicin. We compared single agent docetaxel 100 mg m-2 (D) with the combination of docetaxel 80 mg m-2 and epirubicin 75 mg m-2 (ED). The response rate (72 vs 79%), the progression-free survival (median 9 vs 11 months) and the overall survival (median 18 vs 21 months) were not significantly different between the ED (n=26) and D arms (n=25), respectively. Leucopaenia, nausea and stomatitis were significantly worse with ED. In conclusion, epirubicin should not be administered in combination with taxanes in metastatic breast cancer patients relapsed after an anthracycline-based adjuvant or neoadjuvant therapy.

Independent factors predict supranormal CA 15-3 serum levels in advanced breast cancer patients at first disease relapse.

Data currently available are insufficient to demonstrate a real utility for CA 15-3 in the diagnosis, staging or surveillance of breast cancer patients following primary treatment. The aim of this study was to determine if there was a correlation between supranormal CA 15-3 serum levels and clinical and biological variables in breast cancer patients at first disease relapse. From October 1988 to March 1998, 430 consecutive patients entered the study. Overall CA 15-3 sensitivity was 60.7%. Elevated CA 15-3 levels were found more frequently in patients with liver metastases (74.6%) and in those with pleural effusion (75.7%). CA 15-3 sensitivity was 70.4% in patients with estrogen-receptor-positive (ER+) primary tumors and 45.9% in those with estrogen-receptor-negative (ER-) tumors (p < 0.0001). In patients with a limited extent of disease, marker sensitivity was 57.7% in ER+ tumors and 25.7% in ER- tumors (p < 0.0001). Logistic regression analysis showed ER status, disease extent and pleural effusion as independent variables associated with CA 15-3 positivity. The multivariate Cox analysis showed ER and disease extent as independent variables predicting overall survival, whereas CA 15-3 failed to be statistically significant. CA 15-3 was an independent variable only when the disease extent variable was removed. This study suggests that CA 15-3 in advanced breast cancer patients is a marker of both disease extent and ER status. The direct relationship with ER status indicates that CA 15-3 diagnostic sensitivity in the early detection of disease recurrence could be greater in ER+ patients than in ER- ones. Furthermore, this suggests that patients with elevated CA 15-3 levels could have disease that is more sensitive to hormone manipulation than those with normal CA 15-3 values.

Chromosomal instability and telomere length variations during the life span of human fibroblast clones.

Growth characteristics, karyotype changes, and telomere length variations were analyzed during the life span of 12 anchorage-independent clones isolated from a xeroderma pigmentosum fibroblast strain. After an initial period of comparable active growth, all the clones showed a decline in the growth rate and finally entered a phase of replicative senescence; however, the number of population doublings and the time required to enter senescence varied among the clones. Repeated cytogenetic analyses during culture propagation showed the appearance of chromosome anomalies, mainly telomeric association (tas) and unbalanced translocations. In all the clones the percentage of abnormal mitoses increased with culture passage, but reached different levels (from less than 10% to about 100%). This finding indicates that the replicative block may be associated with differently altered cytogenetic patterns. Specific chromosome arms (5p, 16q, 19q, and 20q) were preferentially involved in tas, suggesting that alterations in chromosome ends may occur which predispose to fusion. In some clones it was possible to demonstrate the origin of marker chromosomes from the evolution of tas. Telomere length analysis by Southern blotting on DNA samples prepared from 7 clones and from the parental cell lines showed that the terminal restriction fragment (TRF) profiles were homogeneous in senescent parental cells and in the clones during the last part of their life in culture, regardless of the degree of karyotype abnormalities. The homogeneity of the TRF profiles supports the hypothesis of a critical telomere length at senescence.

Telomeric fusions in cultured human fibroblasts as a source of genomic instability.

In a human fibroblast clone we studied the evolution, during culture propagation, of a dicentric chromosome consisting of the end-to-end association of the short arm of chromosome 5 and the long arm of chromosome 16. Dual-color fluorescence in situ hybridization (FISH) with painting probes allowed us to define the structure of a variety of derivative chromosomes and to identify the mechanisms by which they originated. Asymmetric interchanges involving the intercentromeric region of the dicentric, bridge-breakage-fusion events, or breaks followed by sister chromatid fusion, originate unstable hetero- or homodicentric chromosomes with deletion or duplication; breakages not followed by reunion, or intradicentric recombination, presumably originate stable rearranged monocentric chromosomes. The variety of the derivatives is extremely large because the observed events may involve any site of the intercentromeric region, although the majority of them occurs after a break in 16qh. The results of this investigation document the evolution through successive steps of a telomeric fusion, a chromosome anomaly frequently observed in tumor and senescent cells. They also demonstrate that in cultured cells of normal origin, starting with this anomaly, various chromosomal mechanisms may produce translocations, duplications, and deletions. The karyotype instability produced by a telomeric fusion can be relevant for carcinogenesis because it may generate genetic changes critical in the multistep process of transformation.

Condensation anomalies and exclusion in micronuclei of rearranged chromosomes in human fibroblasts cultured in vitro.

Anomalies of chromatin condensation, such as fragmentation, uncoiling and pulverization, were observed in XP9UV25, a xeroderma pigmentosum fibroblast clone in which a high proportion of cells carried an end-to-end dicentric chromosome, dic (5;16) (p15.2;q24), that gives rise during propagation in culture to a variety of dicentric and monocentric derivatives. The coiling anomaly affected exclusively part of a rearranged chromosome, in particular the region previously involved in breakage events. The heterochromatic 16q region, which is a preferential breakpoint in the formation of dicentric and monocentric derivatives, was consistently the limit of the uncoiled or pulverized regions. This observation suggests that the anomalous chromatin behavior could derive from alteration of a region relevant for the correct condensation of the chromosome. In XP9UV25 the frequency of nuclei with associated micronuclei increased with time in culture, in parallel with that of mitoses with dicentric chromosomes. In situ hybridization with DNA probes specific for chromosomes 5 and 16 revealed hybridization signals in about 40% of micronuclei. Since the frequency of micronuclei is about ten times less than that of dicentrics, it is probable that only the rearranged chromosomes undergoing coiling anomalies are excluded in micronuclei.

Structural instability of a transmissible end-to-end dicentric chromosome in a xeroderma pigmentosum fibroblast clone.

Cytogenetic analysis was performed in a fibroblast clone (XP9UV25) selected for anchorage-independent growth from an XP strain of normal origin and characterized by the presence of clonal chromosome rearrangements. A dicentric chromosome involving the 5p and 16q telomeric regions was observed in XP9UV25 cells at the fifth passage from colony isolation and at successive passages. The specific anomaly was present with increasing frequency (from 22 to 60% of mitoses) during culture propagation, undergoing rearrangements that gave rise to: 1) (5;16) dicentrics with deletions or duplications of the intercentromeric region; 2) homodicentrics for chromosomes 5 or 16, either end-to-end associations or rearranged; and 3) derivative 5p+ and 16q+ monocentric chromosomes. The frequency of other anomalies involving other chromosomes was negligible. These findings represent the first demonstration that a telomeric association leads to a variety of balanced and unbalanced chromosome rearrangements. These rearrangements may result from asymmetric interchanges between sister chromatids, "bridge-breakage-fusion" events during cell division, breakage and reunion of isochromatids, and breakage followed by healing of the ends. The type of anomaly and the sequence of karyotypic changes we observed in the XP9UV25 clone and their mechanisms of origin may be the same as those occurring during transformation from diploidy to aneuploidy in neoplastic cells.

The first breast cancer screening program in southern Italy: preliminary results from three municipalities of the Naples Province.

AIMS AND BACKGROUND: It has been demonstrated that breast cancer screening induces a 30% reduction of specific mortality. In May 1990, we started a pilot screening program to assess the feasibility of carrying out such a program in Campania (southern Italy). Herein we report the results of the first round of the program from three municipalities (Giugliano, Mugnano and Qualiano) that lie within the local health district no. 23, close to the city of Naples. METHODS: Women between the ages of 50 and 69 years were sent a personalized letter inviting them to attend the screening test; those not responding were sent a second invitation. The screening test consisted of clinical examination followed by two-view mammography. Second-level diagnostic tools were sonography, fine needle aspiration (manual, echo-guided and stereotaxic) and surgical biopsy. RESULTS: Out of 5,732 women invited for the first round, 1,813 (31.6%) attended the screening. Attendance rate was higher among younger women. Ninety-one women were positive at the screening test and underwent further examination (recall rate, 5.0%). Among them, 19 had surgical biopsy (biopsy rate, 1.0%) that led to breast cancer diagnosis in 11 cases. The benign/malignant biopsy rate was 0.73. Detection rate was 6.07 x 1,000 screened women and varied among age categories, increasing within the 60-69 subgroup; detection rate/expected incidence ratio in the overall group was 4.5 and also increased within the older age category. Seven out of 11 cancers were at UICC stage O-I. Among 327 self-referring women, 38 were positive (recall rate, 11.6%), and 14 underwent biopsy (biopsy rate, 4.3%), which showed cancer in 7 cases (benign/malignant biopsy rate, 1.0). In addition, 2 inflammatory cancers were diagnosed without surgical biopsy. Thus 9 cancer cases were detected in this group. Self-referring women differed from responding women in that they had a higher frequency of symptoms or familiar history of cancer, and a higher educational level and awareness of preventive medicine. Clinical examination added no diagnostic advantage in the responding group but did not significantly worsen the recall rate. In the self-referring group, one case of inflammatory cancer was missed by mammography and diagnosed by clinical examination. CONCLUSION: The early results (recall rate = 5%, detection rate/expected incidence ratio = 4.5, benign/malignant biopsy rate = 0.73, advanced cancers = 36.4%) are encouraging and indicate the validity of the program. Strategies to improve attendance rate are planned.

Molecular analysis of the XP-D gene in Italian families with patients affected by trichothiodystrophy and xeroderma pigmentosum group D.

In several patients with the rare hereditary disorder trichothiodystrophy (TTD), a DNA repair defect has been shown to be in the same gene as in xeroderma pigmentosum complementation group D (XP-D). The ERCC-2 gene (excision repair cross-complementing rodent repair deficiency of group 2) has recently been identified as a strong candidate gene for XP-D, since it restores normal UV sensitivity to XP-D cells after transfection. Using Southern blotting, we have analysed the ERCC-2 gene in DNA samples from 28 members of nine Italian families with individuals affected by XP-D (three patients) or by TTD with photosensitivity due to the XP-D defect (eight patients). No major modifications of the ERCC-2 gene were detected with two cDNA probes in either XP-D or TTD patients indicating that the association between TTD and XP-D is not likely to result from a large deletion or rearrangement involving this gene. We found two RFLPs after digestion of the DNA samples with TaqI or MspI, but neither of them could be related to the molecular alteration determining the pathological phenotype. We also analysed a human homologue detected with the hamster sequence isolated by Arrand et al. (1989), which specifically, but partially, complements the DNA repair deficiency in XP-D cells. Our analysis demonstrated that this gene is not the primary gene defective in XP-D. In fact two RFLPs detected with a genomic probe do not co-segregate with the disease in an XP-D family.

Chemotherapy with mitomycin C and vinblastine in pretreated metastatic breast cancer.

AIMS: In February 1986 we began a study to test the activity of mitomycin C (12 mg/m2) plus vinblastine (6 mg/m2) on day 1 of a 28-day cycle (MV) as second or third-line chemotherapy for metastatic breast cancer patients. METHODS: As of February 1988 the study was stopped after 26 patients had been enrolled. The median age of the patients was 54 years (range 35-78); all patients were progressive from chemotherapy; 15 (57.7%) patients were treated as second and 11 (42.3%) as third line; 19 (73.1%) patients had received anthracyclines as first (13 patients) or second-line (6 patients) chemotherapy; 18 (69.2%) patients had visceral involvement; 7 (26.9%) had one metastatic site, 11 (42.3%) two sites, 6 (23.1%) three sites and 2 (7.7%) four sites. RESULTS: Overall, 86 cycles were administered, with a median number of 3 cycles per patient. Toxicity was mild; hematologic side effects required discontinuation of treatment in 3 cases. Vomiting occurred in 3 (11.5%) patients, nausea in 5 (19.2%). Moderate neurologic toxicity was recorded in 6 (23%) patients. No complete and 3 partial responses were observed. The objective response rate was 11.5% (exact 95% confidence interval, 2.4-30.1). Responses occurred independently of disease-free interval, dominant metastatic site, response to previous chemotherapy, previous anthracycline and line of treatment; all responses were recorded in patients under 50 years of age. Kaplan-Meier estimated median time to progression and overall survival were 13 and 40 weeks, respectively. CONCLUSION: The MV regimen was well tolerated but showed little activity in pretreated metastatic breast cancer.

Immune defects in families and patients with xeroderma pigmentosum and trichothiodystrophy.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease characterized by photosensitivity, a high incidence of cancer in sun-exposed portions of the skin and a reduced capacity to repair the u.v.-induced DNA damage. One of the XP mutations (XP-D) has also been identified in patients affected by trichothiodystrophy (TTD), a rare autosomal recessive disease characterized by brittle hair, mental and physical retardation, peculiar face and ichthyosis. However, in these patients there is no evidence of increased skin tumour incidence. Since an impairment of cell-mediated immunity has been proposed as a co-factor in the cancer proneness of XP patients, we investigated the involvement of immune defect(s) in five XP patients, five TTD patients, their parents, and 24 TTD relatives. We evaluated the phenotype of circulating lymphocytes, natural killer (NK) cell lytic activity, target cell binding of NK cells at single cell level and the effect of interferons (IFN) alpha and beta on NK cell activity. The relative proportion of CD3+ and CD4+ circulating lymphocytes was reduced in XP but not in TTD patients. NK cell lytic activity was decreased in XP patients and their mothers, but their fathers showed normal lytic activity. NK activity varied among TTD families: four out of five patients and their relatives presented low NK cell activity, and one family was normal. In TTD family members, NK activity increased after incubation with IFN-alpha or IFN-beta, but never reached normal values. In contrast, in XP patients and their mothers, the defect was almost completely corrected after in vitro incubation with IFN-alpha or IFN-beta. Our study indicates impaired NK lytic activity in the majority of TTD and XP patients and that this defect is present also in members of their families. In addition, XP patients present a low number of circulating T cells. These multiple abnormalities, together with DNA repair defects, could be related to the increased cancer risk in XP patients.

Trisomy 21 mosaicism in two subjects from two generations.

In the course of a chromosome fragility investigation on the cancer prone hereditary disorder xeroderma pigmentosum, a low proportion of cells with a 47,XY,+21 karyotype was found in lymphocyte cultures of a patient not showing any Down syndrome symptom. The presence of trisomy 21 mosaicism was demonstrated also in peripheral blood of the healthy father and confirmed by "chromosome painting" that allowed a rapid detection of chromosomes 21 on metaphase cells and interphase nuclei. The trisomic cell line was not detected in fibroblast cultures. The analysis of chromosome 21 heteromorphism indicated that in both subjects the mosaic could result from either a diploid or an aneuploid zygote. Since in the trisomic cell line of the father and the son the extra chromosome 21 seems to be the same, a predisposition toward mitotic errors (non-disjunction or anaphase lagging) may be postulated, leading to the recurrent gain or loss of a specific chromosome 21. In order to test the hypothesis of an abnormal mitotic behaviour of the chromosome 21, we investigated the centromere separation index and the DNA restriction pattern in Southern blots probed with satellite DNA sequences specific for chromosome 21 centromere. Both the approaches did not reveal any peculiar feature that may account for the genetically determined proneness to mitotic error observed in the family.

Different rate of chromosome breakage in human fibroblast strains after storage in liquid nitrogen.

Cytogenetic investigation was carried out on fibroblasts stored in liquid nitrogen during a period of 7-99 months. Cell strains were from 9 individuals, 2 of whom were affected by xeroderma pigmentosum group C (XPC), and 2 XPC heterozygotes. In cell samples from 3 normal subjects and from 1 patient, high frequencies of abnormal mitoses were observed at the first passage after thawing, which returned to normal values after a few subcultures. The most frequent lesions were chromosome gaps and breaks. The cells damaged the most were those from one XP patient. These findings indicate that cells from some individuals are hypersensitive to clastogenic factors acting during freezing and thawing procedures. This sensitivity could be related to the genetic constitution, although the XP homozygous condition is not an essential or sufficient factor.

Novel Chinese hamster ultraviolet-sensitive mutants for excision repair form complementation groups 9 and 10.

In this paper we demonstrate that the mutants CHO7PV and CHO4PV isolated by us from the CHO-K1 prol- cell line represent two new complementation groups of UV-sensitive excision repair-defective rodent mutants. We have classified the mutant CHO7PV as representative of Group 9 and CHO4PV as representative of Group 10. Cellular and biochemical characterization of these mutants indicates that they are moderately sensitive to a broad spectrum of mutagens (UV and mono- and bifunctional alkylating agents), partially unable to perform UV-induced DNA repair synthesis, and partially defective in the incision step of the DNA excision repair pathway and in the removal of the two main lesions caused by UV [cyclobutane pyrimidine dimers and (6-4) photo-products]. In terms of UV survival and incision, CHO4PV is apparently more defective than CHO7PV (40% and 50% of wild-type survival, respectively, and 55% and 75% of wild-type incision), whereas when repair DNA synthesis and lesion removal are compared, CHO7PV seems to be more severely affected (30% of wild-type unscheduled DNA synthesis in CHO7PV and 60% in CHO4PV). This suggests a subtlety in the relation between removal of these specific lesions and overall repair capacity and survival.

Chromosome rearrangements in normal fibroblasts from xeroderma pigmentosum homozygotes and heterozygotes.

Chromosome analysis was carried out in cultured fibroblasts from unaffected skin of five unrelated xeroderma pigmentosum (XP) patients and nine family members. Structural chromosome changes were observed in cultures from all examined individuals. Furthermore, in one XPD patient and in one XPC patient and his parents, cytogenetically abnormal clones were detected. Some of these clones were present starting from the primary explant. This cytogenetic pattern is similar to that observed in an XPC patient previously studied by us. The analysis of breakpoint distribution from clonal and non-clonal chromosome rearrangements showed that some breakpoints were more frequent and common to different families or to different family members although definite evidence of preferential involvement of chromosome bands was not obtained. This investigation indicates that there is a consistent tendency toward chromosome instability in XP mutation carriers. The instability could be related to the multiple chromosome anomalies characterizing skin tumors in XP subjects.