Asselineau, Léon Auguste

Tumour specimens from 23 patients with thyroid carcinoma, 22 patients with thyroid adenoma, 3 with Graves' disease, and tissues from 8 normal thyroid glands were analyzed by Southern blot hybridization for the physical state of c-myc and c-fos proto-oncogenes. In 4 patients, both the primary tumour and lymph node metastases were analyzed. No amplification or rearrangement of the two proto-oncogenes was detected. Total RNAs were also analyzed. Elevated levels of the 2.4 kb c-myc RNA and of the 2.2 kb c-fos RNA were found in 13/23 (57%) and 14/23 (61%) of the cancer patients, respectively. High levels of c-myc transcripts were more frequently found in thyroid carcinomas with unfavourable prognosis. Concomitant elevated levels of both c-myc and c-fos RNAs were found in 8 cancers. High levels of c-myc RNA were also found in 1 out of 22 specimens of adenoma, in 1 specimen of Graves' disease and in 2 normal thyroid glands. High levels of c-fos RNA were found in 20 of the 22 adenoma samples and in 2 out of 8 normal thyroid tissues. These data indicate that the overexpression of c-myc and c-fos genes is independent of an alteration of the loci. The high levels of c-fos found in adenoma may be associated with the differentiation state of these tumours.

Can we reduce the incidence of second primary malignancies occurring after radiotherapy? A critical review

Second primary malignancies (SPMs) occurring after oncological treatment have become a major concern during the past decade. Their incidence has long been underestimated because most patients had a short life expectancy after treatment or their follow-up was shorter than 15 years. With major improvement of long-term survival, longer follow-up, cancer registries and end-result programs, it was found that the cumulative incidence of SPM could be as high as 20% of patients treated by radiotherapy. This cumulative proportion varies with several factors, which ought to be studied more accurately. The delay between irradiation and solid tumor emergence is seldom shorter than 10 years and can be as long as half a century. Thus, inclusion in a cohort of patients with a short follow-up leads to an underestimation of the proportion of SPM caused by treatment, unless actuarial cumulative incidence is computed. The incidence varies with the tissue and organs, the age of the patient at treatment, hereditary factors, but also, and probably mainly, with dose distribution, size of the irradiated volume, dose, and dose-rate. An effort toward a reduction in their incidence is mandatory. Preliminary data suggest that SPMs are mainly observed in tissues having absorbed doses above 2 Gy (fractionated irradiation) and that their incidence increases with the dose. However, in children thyroid and breast cancers are observed following doses as low as 100 mGy, and in adults lung cancers have been reported for doses of 500 mGy, possibly due to interaction with tobacco. The dose distribution and the dose per fraction have a major impact. However, the preliminary data regarding these factors need confirmation. Dose-rates appear to be another important factor. Some data suggest that certain patients, who could be identified, have a high susceptibility to radiocancer induction. Efforts should be made to base SPM reduction on solid data and not on speculation or models built on debatable hypotheses regarding the dose-carcinogenic effect relationship. In parallel, radiation therapy philosophy must evolve, and the aim of treatment should be to deliver the minimal effective radiation therapy rather than the maximal tolerable dose.

Effects of switching aromatase inhibitors on arthralgia: the ATOLL study

Abstract #1142

Background: Aromatase inhibitors (AIs) are standard adjuvant therapy in postmenopausal women (PMW) with hormone receptor-positive breast cancer (HR+BC). The estrogen-deficient environment induced by AIs may predispose women to increased bone loss and arthralgia. Switching from one AI to another has been shown to improve arthralgia. However, clinical trial data documenting the course of joint pain symptoms in switching studies has been sparse. The Articular Tolerance of Letrozole (ATOLL) study evaluates the tolerability of letrozole (L) in patients who were switched from anastrozole (A) due to severe joint pain.
 Objectives: This study included PMW with HR+BC who experienced severe joint pain with A requiring discontinuation and then switched to L. The aim of the study was to (i) determine the incidence of L discontinuation due to joint pain (ii) identify predictive factors for L tolerance.
 Methods: Only PMW with HR+ BCwho experienced severe joint pain on A requiring discontinuation were eligible for this 6-month prospective open-label, multi-centre trial. Treatment with L was initiated following a 1 month washout period. Pain assessment was done by a oncologist just prior to L initiation and after six months of follow up. Outcomes were based on patient reports of joint pain after initiating L. A central review was done by a rheumatologist. Statistical evaluations were determined on a 95% CI, and correlations were performed using a Cox model.
 Results: 179 PMW with HR+ breast cancer (mean age 61.3 ± 8.4) were eligible. The mean duration of A treatment prior to discontinuation was 14.6 ± 10.59 months with 126 (73.7%) on A for more than 6 months. At the end of the 6 month follow-up, 128 patients (71.5%) remained on L and continued by choice while 51(28.5%) patients discontinued L due to worsening of joint pain;73.5% patients discontinued due to arthralgia and 21% due to muscle pain . Hands, knees and spine were the most commonly affected joints. There was no association between L discontinuation with age, duration of menopause, socio-demographic status or previous joint disorders including osteoarthritis. The predictor of L discontinuation was significant only for the duration of the previous A treatment (p=0.04).
 Conclusion: These data suggest switching from anastrozole to letrozole may help to maintain the benefit of AI therapy in patients who complain with severe joint pain and support the reported findings of Renshaw et al that more than 50% of women obtained relief of joint pain by switching from one AI to another. Symptomatic arthralgia due to prolonged use of A reduced the usefulness of switching to L in this patient cohort, therefore, switching from one AI to the other at the onset of symptoms may help to maintain the benefit of AI therapy in patients who complain of severe joint pain.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1142.

Biological stress response terminology: Integrating the concepts of adaptive response and preconditioning stress within a hormetic dose-response framework

Many biological subdisciplines that regularly assess dose-response relationships have identified an evolutionarily conserved process in which a low dose of a stressful stimulus activates an adaptive response that increases the resistance of the cell or organism to a moderate to severe level of stress. Due to a lack of frequent interaction among scientists in these many areas, there has emerged a broad range of terms that describe such dose-response relationships. This situation has become problematic because the different terms describe a family of similar biological responses (e.g., adaptive response, preconditioning, hormesis), adversely affecting interdisciplinary communication, and possibly even obscuring generalizable features and central biological concepts. With support from scientists in a broad range of disciplines, this article offers a set of recommendations we believe can achieve greater conceptual harmony in dose-response terminology, as well as better understanding and communication across the broad spectrum of biological disciplines.

Long-term results of breast cancer irradiation treatment with low-dose-rate external irradiation

PURPOSE

The aim of this study was to assess beam therapy with low-dose-rate (LDR) external irradiation in a group of patients with breast cancer.

METHODS AND MATERIALS

This trial compared, from 1986 to 1989, patients with advanced breast cancer treated either by conventional fractionation or low-dose-rate (LDR) external radiotherapy (dose-rate 15 mGy/min, 5 sessions of 9 Gy delivered on 5 consecutive days).

RESULTS

A total of 21 patients were included in the fractionated therapy arm. At follow-up 15 years after treatment, 7 local recurrences had occurred, 3 patients had died of cancer, 18 patients were alive, 10 were without evidence of disease, and 6 had evidence of disease. A total of 22 patients had been included in the LDR arm of the study. Of these, 11 had received a dose of 45 Gy; thereafter, in view of severe local reactions, the dose was reduced to 35 Gy. There was no local recurrence in patients who had received 45 Gy, although there were 2 local recurrences among the 11 patients after 35 Gy. The sequelae were severe in patients who received 45 Gy but were comparable to those observed in patients treated by fractionated radiotherapy who received 35 Gy. The higher efficacy of tumor control in patients treated by LDR irradiation as well as the lower tolerance of normal tissue are probably related to the lack of repopulation.

CONCLUSION

Although the patient numbers in this study are limited, based on our study results we conclude that the data for LDR irradiation are encouraging and that further investigation is warranted.

The debate on the use of linear no threshold for assessing the effects of low doses

From December 2004 to July 2005, three reports on the effects of low doses of ionising radiation were released: ICRP (2004), the joint report of the French Academies of Science and Medicine (Tubiana et al 2005), and a report from the American Academy of Sciences (BEIR VII 2005). These reports quote the same recent articles on the biological effects of low doses, yet their conclusions diverge. The French report concludes that recent biological data show that the efficacy of defense mechanisms is modulated by dose and dose rate and that linear no threshold (LNT) is no longer plausible. The ICRP and the BEIR VII reports recognise that there are biologic arguments against LNT but feel that there are not sufficient biological proofs against it to change risk assessment methodology and subsequent regulatory policy based on LNT. They point out the remaining uncertainties and the lack of mechanistic explanations of phenomena such as low dose hyperlethality or the adaptive response. In this context, a critical analysis of the available data is necessary. The epidemiological data and the experimental data challenge the validity of the LNT hypothesis for assessing the carcinogenic effect of low doses, but do not allow its exclusion. Therefore, the main criteria for selecting the most reliable dose-effect relationship from a scientific point of view should be based on biological data. Their analysis should help one to understand the current controversy.

Twenty-five years of follow-up in patients with operable breast carcinoma: correlation between clinicopathologic factors and the risk of death in each 5-year period

BACKGROUND

Some investigators have suggested a decreased prognostic value for conventional prognostic factors over time in patients with breast carcinoma. The objective of this study was to assess the effect of prognostic factors on the risk of death in patients with breast carcinoma over a long follow-up.

METHODS

The authors assessed clinicopathologic prognostic factors in patients with early-stage breast carcinoma over a follow-up > 25 years and analyzed the variation of their effect on death in consecutive 5-year follow-up intervals. The study included 2410 women who primarily underwent complete surgical resection. Time-dependent variables were analyzed by using different multivariate models.

RESULTS

Four factors were related strongly to the risk of death in the first 5 years: tumor size, histologic grade, the number of involved axillary lymph nodes, and age at diagnosis. After 10-15 years of follow-up, only age at diagnosis was related to the risk of death. The effect of powerful prognostic factors, except age at diagnosis, on the risk of death was time limited, and no effects or very small effects were detectable after 10 years of follow-up.

CONCLUSIONS

Conventional and widely accepted prognostic factors may explain a significant portion of early deaths among patients with early-stage breast carcinoma, but they were of limited value to explain late mortality, that also may be influenced by late events, such as new primary malignancies and treatment complications. Cancer 2006. (c) 2006 American Cancer Society.

Recent reports on the effect of low doses of ionizing radiation and its dose-effect relationship

Recently, the risk associated with low doses of ionizing radiation has gained new interest. Here, we analyze and discuss the major differences between two reports recently published on this issue; the report of the French Academy of Sciences and of the French Academy of Medicine published in March 2005, and the BEIR VII-Phase 2 Report of the American National Academy of Sciences published as a preliminary version in July 2005. The conclusion of the French Report is that the linear no-threshold relationship (LNT) may greatly overestimate the carcinogenic effect of low doses (<100 mSv) and even more that of very low doses (<10 mSv), such as those delivered during X-ray examinations. Conversely, the conclusion of the BEIR VII report is that LNT should be used for assessing the detrimental effects of these low and very low doses. The causes of these diverging conclusions should be carefully examined. They seem to be mostly associated with the interpretation of recent biological data. The point of view of the French Report is that these recent data are incompatible with the postulate on which LNT is implicitly based, namely the constancy of the carcinogenic effect per unit dose, irrespective of dose and dose rate.

Measuring progress against cancer in Europe: has the 15% decline targeted for 2000 come about?

BACKGROUND

Against a background of increasing cancer rates in the mid-1980s, Europe Against Cancer launched an ambitious programme aiming to reduce cancer mortality by 15% by the year 2000. A programme of activities and research, focussing on three major themes [prevention (particularly tobacco control), screening, and education and training], was developed together with the European Code Against Cancer.

METHODS

To evaluate the outcome of the programme, all cancer mortality data were abstracted for each member state of the European Union (EU) until the most recent year available. For each gender group in each member state, age-specific rates were estimated for 2000. For each country-gender grouping, the standardized mortality rate (SMR) and expected numbers of deaths in 2000 were calculated based on the age-specific rates for 1985 and the population estimates for 2000. The ratio of the SMR in 2000 to that of 1985, was used as the measure to compare mortality rates.

RESULTS

In 1985, there were 850 194 cancer deaths in the EU. Based solely on demographic considerations, this number was expected to rise to 1 033 083 in the year 2000. Between 1985 and 2000, the number of cancer deaths increased in both men (+12%) and women (+9%). The target of a 15% reduction in the expected numbers of cancer deaths in the EU was not met, although the 10% reduction in number of deaths expected in men and 8% in women, along with a 11% reduction in risk of cancer death in men and a 10% reduction in women, was noteworthy. Only Austria and Finland achieved the 15% reductions in deaths in both men and women. The UK and Luxembourg (where the small population and annual number of deaths make interpretation difficult) came close to meeting these targets, as did Italy. Portugal and Greece had the poorest performance, with increases in each gender group.

CONCLUSIONS

Cancer deaths in the EU were expected to rise from 850 194 in 1985 to 1 033 083 in 2000. It is estimated that there will be 940 510 cancer deaths that year, due to the decline in risk observed since 1985. The Europe Against Cancer programme appears to have been associated with the avoidance of 92 573 cancer deaths in the year 2000. With few exceptions, most countries are experiencing declining trends in cancer death rates, which seem set to continue, at least in the near future. Renewed tobacco control efforts are clearly needed for women, and there is a strong case for the introduction of organized breast and cervix screening programmes in all member states. Continuing to emphasize prevention within cancer control will help to promote the continuing decline in death rates in the future.

[Stem cell colloquy: conclusion]

The stem cell data presented and discussed during the symposium raise the hope that important medical progress can be made in several fields: neuro-degenerative diseases, those linked to cellular deficit, some aspects of aging linked to cellular degeneration, and the treatment of cancers that may harm normal tissues at risk of being infiltrated by malignant cells. Three main types of stem cells are available. (i) Those present in normal adult tissue: contrary to what was believed, some data suggest that certain adult stem cells have a great plasticity (they can differentiate into cells different from those in tissues from which they were taken) and can proliferate in vitro without losing their properties. Nevertheless, their use faces several obstacles: in ill or elderly subjects, then these cells can be limited in number or not multiply well in vitro. In this case, auto-grafting of the cells cannot be used. They must be sought in another subject, and allo-grafting causes difficult and sometimes insoluble problems of immunological tolerance. (ii) Embryonic stem cells from surplus human embryos, obtained by in vitro fertilisation, which the parents decide not to use: these cells have a great potential for proliferation and differentiation, but can also encounter problems of immunological intolerance. (iii) Cells obtained from cell nuclear transfer in oocytes: these cells are well tolerated, since they are genetically and immunologically identical to those of the host. All types of stem cells can be obtained with them. However, they do present problems. For obtaining them, female oocytes are needed, which could lead to their commercialization. Moreover, the first steps for obtaining these cells are identical to those used in reproductive cloning. It therefore appears that each type of cell raises difficult scientific and practical problems. More research is needed to overcome these obstacles and to determine which type of stem cell constitutes the best solution for each type of disease and each patient. There are three main ethical problems: (a) to avoid the commercialization of stem cells and oocytes (this can be managed through strict regulations and the supervision of authorized laboratories); (b) to avoid that human embryos be considered as a mere means to an end (they should only be used after obtaining the informed consent of the parents; the conditions of their use must be well defined and research programs must be authorized); (c) to avoid that research on stem cell therapy using cell nuclear replacement opens the way to reproductive cloning (not only should reproductive cloning be firmly forbidden but authorization for cell nuclear transfer should be limited to a small number of laboratories). Overall, it appears that solutions can be found for administrative and ethical problems. Harmonisation of international regulations would be desirable in this respect, in allowing at the same time each country to be responsible for its regulations. A last ethical rule should be implemented, not to give patients and their families false hopes. The scientific and medical problems are many, and the solutions will be long and difficult to find. Regenerative medicine opens important avenues for research, but medical progress will be slow.