Recent advances: oncology

International Validation of the SORG Machine-learning Algorithm for Predicting the Survival of Patients with Extremity Metastases Undergoing Surgical Treatment

BACKGROUND

The Skeletal Oncology Research Group machine-learning algorithms (SORG-MLAs) estimate 90-day and 1-year survival in patients with long-bone metastases undergoing surgical treatment and have demonstrated good discriminatory ability on internal validation. However, the performance of a prediction model could potentially vary by race or region, and the SORG-MLA must be externally validated in an Asian cohort. Furthermore, the authors of the original developmental study did not consider the Eastern Cooperative Oncology Group (ECOG) performance status, a survival prognosticator repeatedly validated in other studies, in their algorithms because of missing data.

QUESTIONS/PURPOSES

(1) Is the SORG-MLA generalizable to Taiwanese patients for predicting 90-day and 1-year mortality? (2) Is the ECOG score an independent factor associated with 90-day and 1-year mortality while controlling for SORG-MLA predictions?

METHODS

All 356 patients who underwent surgery for long-bone metastases between 2014 and 2019 at one tertiary care center in Taiwan were included. Ninety-eight percent (349 of 356) of patients were of Han Chinese descent. The median (range) patient age was 61 years (25 to 95), 52% (184 of 356) were women, and the median BMI was 23 kg/m2 (13 to 39 kg/m2). The most common primary tumors were lung cancer (33% [116 of 356]) and breast cancer (16% [58 of 356]). Fifty-five percent (195 of 356) of patients presented with a complete pathologic fracture. Intramedullary nailing was the most commonly performed type of surgery (59% [210 of 356]), followed by plate screw fixation (23% [81 of 356]) and endoprosthetic reconstruction (18% [65 of 356]). Six patients were lost to follow-up within 90 days; 30 were lost to follow-up within 1 year. Eighty-five percent (301 of 356) of patients were followed until death or for at least 2 years. Survival was 82% (287 of 350) at 90 days and 49% (159 of 326) at 1 year. The model's performance metrics included discrimination (concordance index [c-index]), calibration (intercept and slope), and Brier score. In general, a c-index of 0.5 indicates random guess and a c-index of 0.8 denotes excellent discrimination. Calibration refers to the agreement between the predicted outcomes and the actual outcomes, with a perfect calibration having an intercept of 0 and a slope of 1. The Brier score of a prediction model must be compared with and ideally should be smaller than the score of the null model. A decision curve analysis was then performed for the 90-day and 1-year prediction models to evaluate their net benefit across a range of different threshold probabilities. A multivariate logistic regression analysis was used to evaluate whether the ECOG score was an independent prognosticator while controlling for the SORG-MLA's predictions. We did not perform retraining/recalibration because we were not trying to update the SORG-MLA algorithm in this study.

RESULTS

The SORG-MLA had good discriminatory ability at both timepoints, with a c-index of 0.80 (95% confidence interval 0.74 to 0.86) for 90-day survival prediction and a c-index of 0.84 (95% CI 0.80 to 0.89) for 1-year survival prediction. However, the calibration analysis showed that the SORG-MLAs tended to underestimate Taiwanese patients' survival (90-day survival prediction: calibration intercept 0.78 [95% CI 0.46 to 1.10], calibration slope 0.74 [95% CI 0.53 to 0.96]; 1-year survival prediction: calibration intercept 0.75 [95% CI 0.49 to 1.00], calibration slope 1.22 [95% CI 0.95 to 1.49]). The Brier score of the 90-day and 1-year SORG-MLA prediction models was lower than their respective null model (0.12 versus 0.16 for 90-day prediction; 0.16 versus 0.25 for 1-year prediction), indicating good overall performance of SORG-MLAs at these two timepoints. Decision curve analysis showed SORG-MLAs provided net benefits when threshold probabilities ranged from 0.40 to 0.95 for 90-day survival prediction and from 0.15 to 1.0 for 1-year prediction. The ECOG score was an independent factor associated with 90-day mortality (odds ratio 1.94 [95% CI 1.01 to 3.73]) but not 1-year mortality (OR 1.07 [95% CI 0.53 to 2.17]) after controlling for SORG-MLA predictions for 90-day and 1-year survival, respectively.

CONCLUSION

SORG-MLAs retained good discriminatory ability in Taiwanese patients with long-bone metastases, although their actual survival time was slightly underestimated. More international validation and incremental value studies that address factors such as the ECOG score are warranted to refine the algorithms, which can be freely accessed online at https://sorg-apps.shinyapps.io/extremitymetssurvival/.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Eudragit S-100 entrapped chitosan microspheres of valdecoxib for colon cancer

COX-2 inhibitors have demonstrated beneficial effects in colorectal cancer. The purpose of this study was to prepare and evaluate the colon specific microspheres of COX-2 inhibitors using valdecoxib as a model drug. Mucoadhesive core microspheres were prepared using chitosan as polymer and entrapped within Eudragit S 100 for colon targeting. FTIR spectrum of selected, coated microspheres showed peaks of valdecoxib at 3377, 3250, 1334 and 1155 cm(-1). XRD showed amorphous character and DSC showed depressed broad endotherm of valdecoxib at 169.07 degrees C, which may be attributed to dilution effect by the amorphous polymer. The coated microspheres were spherical with an average size of 90 mum. Storage of the microspheres at 40 degrees C/75% relative humidity for 6 months indicated no significant drug degradation. The coated microspheres did neither release the drug in acidic pH of stomach (pH 1.2) nor in small intestinal pH between 5 to 6.8, and the release started at pH 7.4, indicting perfect colonic delivery. The coated microspheres pretreated with phosphate buffer pH 7.4 for 30 min, when applied to mucosal surface of freshly excised goat colon, showed good mucoadhesion. The drug release at pH 7.4 and good mucoadhesive property of the microspheres make the system ideal for colonic delivery.

Prognostic factors in patients with recently diagnosed incurable cancer: a systematic review

GOALS OF WORK

To review the literature and develop a conceptual framework about prognostic factors for people presenting to medical oncologists with recently diagnosed incurable cancer.

MATERIALS AND METHODS

Medline was searched from January 2000 to October 2003 to identify articles testing associations between clinical or laboratory variables and survival time in adults with advanced solid tumours and median survival of 3 to 24 months. We recorded how frequently prognostic factors were significantly associated with survival in univariable and multivariable analyses.

RESULTS

There were 53 studies included. The factors associated with survival were organised into four categories related to attributes of the host the tumour, the treatment and the interactions between host, tumour and treatment (symptoms, quality of life, performance status and laboratory tests). Co-morbidity was consistently associated with shorter survival. Age and gender were not consistently associated with survival duration, except in lung cancer where females survived longer. Tumour-related factors associated with shorter survival included primary tumour (lung), metastatic site (liver, brain and visceral) and disease extent. Symptoms associated with shorter survival included those of the anorexia-cachexia syndrome, dyspnoea, pain and impaired physical well being. Performance status was strongly associated with survival in most studies. Laboratory tests associated with shorter survival included anaemia, thrombocytopenia, hypoalbuminaemia and elevated serum levels of both alkaline phosphatase and lactate dehydrogenase.

CONCLUSION

Prognostic factors in patients with advanced cancer can be conceptualised as attributes of the host, tumour, treatment and interactions between the three reflected in symptoms, quality of life performance status and laboratory tests.

Mitochondrial and Nuclear DNA Damage Induced by Curcumin in Human Hepatoma G2 Cells

Curcumin is extensively used as a spice and pigment and has anticarcinogenic effects that could be linked to its antioxidant properties. However, some studies suggest that this natural compound possesses both pro- and antioxidative effects. In this study, we found that curcumin induced DNA damage to both the mitochondrial and nuclear genomes in human hepatoma G2 cells. Using quantitative polymerase chain reaction and immunocytochemistry staining of 8-hydroxydeoxyguanosine, we demonstrated that curcumin induced dose-dependent damage in both the mitochondrial and nuclear genomes and that the mitochondrial damage was more extensive. Nuclear DNA fragments were also evident in comet assays. The mechanism underlies the elevated level of reactive oxygen species and lipid peroxidation generated by curcumin. The lack of DNA damage at low doses suggested that low levels of curcumin does not induce DNA damage and may play an antioxidant role in carcinogenesis. But at high doses, we found that curcumin imposed oxidative stress and damaged DNA. These data reinforce the hypothesis that curcumin plays a conflicting dual role in carcinogenesis. Also, the extensive mitochondrial DNA damage might be an initial event triggering curcumin-induced cell death.

Chemoprevention of colorectal cancer: ready for routine use?

In the third millennium, preventive medicine is becoming a cornerstone in our concept of health. Colorectal cancer (CRC) prevention, in particular, has become an important goal for health providers, physicians and the general public. CRC fits the criteria of a disease suitable for chemopreventive interventions. It is a prevalent disease that is associated with considerable mortality and morbidity rates, with more than 1,000,000 new cases and 500,000 deaths expected, worldwide, in 2004. CRC has a natural history of transition from precursor to malignant lesion that spans, on average, 15-20 years, providing a window of opportunity for effective interventions and prevention. A pre-malignant precursor lesion (i.e. adenoma) usually precedes cancer, and helps to identify a subset of the population that is at increased risk of harbouring and developing cancer. Science and technology have evolved to a point where we are able to use our knowledge of cancer biology to identify individuals at risk and interrupt the process of malignant transformation at the level of the pre-cancerous lesion. Recent progress in molecular biology and pharmacology enhances the likelihood that cancer prevention will increasingly rely on chemoprevention. Chemoprevention, a new emerging science, means the use of agents to inhibit, delay or reverse carcinogenesis. Recent observations suggest a number of potential targets for chemoprevention. Many agents have potential benefit but only modest chemopreventive efficacy in clinical trials. There is much evidence suggesting an inverse relationship between aspirin or non-steroidal anti-inflammatory drug (NSAID) consumption and CRC incidence and mortality. However, NSAID consumption is not problem-free; 1997 data show 107,000 hospitalisations and 16,500 deaths due to NSAID consumption in the U.S. alone. Therefore, although chemoprevention of CRC is already possible, drugs that have more acceptable side-effect profiles than the currently available NSAIDs are required. Cyclo-oxygenase (COX)-2-specific inhibitors, which have an improved safety profile compared to traditional NSAIDs that inhibit both the COX-1 and COX-2 enzymes, seem to be well-suited drug candidates for CRC prevention. The inhibition of the growth of pre-cancerous and cancerous cells without affecting normal cells is the ultimate aim of cancer treatment and is of particular importance in chemoprevention studies, which may be long term in nature, involving healthy subjects and minimal toxicity. Cancer prevention is certain to be a significant focus of research and intervention in the coming years, propelled by the realisation that we will be able to identify both individuals susceptible to specific cancers as well as the molecular targets that can alter or stop the carcinogenesis process. Pharmacology and genetics are collaborating to develop new chemoprevention agents designed to affect molecular targets linked to specific premalignant or predisposing conditions.

Do cancer patients benefit from short-term contact with a general practitioner following cancer treatment? A randomised, controlled study

GOALS OF WORK

To investigate whether increased contact with the patient's general practitioner (GP) soon after cancer treatment can increase patient quality of life (QoL) and satisfaction with follow-up.

PATIENTS AND METHODS

A randomised controlled study with 91 patients from one Norwegian municipality. The intervention group got a 30-min invited consultation with the patient's GP and an invitation to further GP follow-up. Quality of life and patient satisfaction with diagnosis, treatment and overall care were measured with validated instruments.

MAIN RESULTS

Relatives' satisfaction with care increased over 6 months in the intervention group (P = 0.018), but otherwise, there was no difference between the intervention and control groups concerning QoL, satisfaction with care or number of consultations. Patient satisfaction with care showed a tendency to increase when treatment intent was curative. Some functional QoL measures and satisfaction tended to increase during the first 6 months after treatment. Free text comments suggested that some patients appreciated the contact with their GP.

CONCLUSION

Some cancer patients benefit from follow-up by their GP. The way to perform this kind of follow-up in primary care, and who these cancer patients are, should be further studied. Short follow-up time and an urban setting may have contributed to the lack of group differences in our study, but patients treated for cancer may have limited need for follow-up as long as they feel well and the situation remains stable.

Evaluación de los proyectos de investigación clínica en un centro monográfico de cáncer

BACKGROUND AND OBJECTIVE

The number of clinical trials in cancer patients has experienced an important growth during last years. However, it is difficult to find data showing this activity in Spanish Hospitals. This study analyses the clinical trials data bases between 1996 and 2002 in a cancer center.

MATERIAL AND METHODS

We perform a descriptive analysis of data from: selection of protocols, origin of proposals, sponsors, investigators, studies performed and published; demographic data about patients and phase of the studies in which they have been included.

RESULTS

Evaluation was undertaken with a standardised protocol review assessment. 337 proposals of clinical trials were evaluated during 1996-2002, with a decreasing acceptance index (62.5% to 39.18%, respectively), the number of proposals has grown from 16 in 1996 to 74 in 2002. The general recruitment index was 6.64%. Between 1995-2002, 1479 patients were registered; only 5% were older than 75 years. Pharmaceutical Companies sponsored the majority of the studies, although Co-operative Groups promote an important number of studies, especially in Haematology and Radiotherapy. Thirteen studies performed between 1996-1998 had been published, and 3 more are accepted for publication (69.5%).

CONCLUSIONS

The number of patients included in clinical trials is limited and older patients are not well represented in them.

Randomised controlled trial of a shared care programme for newly referred cancer patients: bridging the gap between general practice and hospital

OBJECTIVE

To determine the effect of a shared care programme on the attitudes of newly referred cancer patients towards the healthcare system and their health related quality of life and performance status, and to assess patients' reports on contacts with their general practitioner (GP).

SETTING

Department of Oncology at Aarhus University Hospital and general practices.

DESIGN

Randomised controlled trial in which patients completed questionnaires at three time points. The shared care programme included transfer of knowledge from the oncologist to the GP, improved communication between the parties, and active patient involvement.

PARTICIPANTS

248 consecutive cancer patients recently referred to the department.

MAIN OUTCOME MEASURES

Patients' attitudes towards the healthcare services, their health related quality of life, performance status, and reports on contacts with their GPs.

RESULTS

The shared care programme had a positive effect on patient evaluation of cooperation between the primary and secondary healthcare sectors. The effect was particularly significant in men and in younger patients (18-49 years) who felt they received more care from the GP and were left less in limbo. Young patients in the intervention group rated the GP's knowledge of disease and treatment significantly higher than young patients in the control group. The number of contacts with the GP was significantly higher in the intervention group. The EORTC quality of life questionnaire and performance status showed no significant differences between the two groups.

CONCLUSIONS

An intersectoral shared care programme in which GPs and patients are actively involved has a positive influence on patients' attitudes towards the healthcare system. Young patients and men particularly benefit from the programme.

Nonsteroidal anti-inflammatory drugs, apoptosis, and colon-cancer chemoprevention

Nonsteroidal anti-inflammatory drugs (NSAIDs) can inhibit colorectal tumorigenesis and are among the few agents known to be chemopreventive. Epidemiological studies and experiments with animals have shown that NSAIDs have powerful anticolorectal cancer properties, but the mechanism of these effects remains unclear. NSAIDs can inhibit neoplastic growth by inducing apoptosis in cancer cells; the way they do this is currently an area of intense investigation. The most well-characterised pharmacological feature of NSAIDs is their inhibition of the enzyme cyclo-oxygenase (COX), which catalyses the synthesis of prostaglandins. Several studies have shown that COX inhibition prevents cell proliferation and promotes apoptosis. The chemopreventive effects of NSAIDs are thought to occur via this pathway. Other observations indicate that NSAIDs also promote apoptosis through mechanisms that are independent of COX inhibition. This idea is supported by the finding that compounds that are structurally similar to NSAIDs, but do not inhibit COX, also have chemopreventive and proapoptotic properties. COX-dependent and COX-independent mechanisms of apoptosis induction are not mutually exclusive, and it is likely that both have a role in the biological activity of NSAIDs. Knowledge of how NSAIDs prevent neoplastic growth will greatly aid the design of better chemopreventive drugs and novel treatments for colorectal cancer.

When the treatment goal is not cure: are cancer patients equipped to make informed decisions?

PURPOSE

Informed decision making now is considered the underpinning of ethical medical practice. We aimed to determine the extent to which patients with incurable cancer are adequately informed of their prognosis and treatment options and encouraged to participate in treatment decisions.

PATIENTS AND METHODS

One hundred eighteen cancer patients with incurable disease presenting for an initial consultation with one of nine oncologists at two Sydney tertiary referral hospitals participated in the study. Consultations were recorded on audiotape to permit a content analysis of doctor-patient interactions. We devised a coding system to assess disclosure of information and to evaluate doctor encouragement of patient participation in treatment decision making. Patient recall, satisfaction, anxiety, and perceptions of the decision-making process were assessed to determine the effects of informed decision making on patient outcomes.

RESULTS

Most patients were informed about the aim of anticancer treatment (84.7%), that their disease was incurable (74.6%), and about life expectancy (57.6%). An alternative to anticancer treatments was presented to 44.1%, 36.4% were informed about how anticancer treatment would affect quality of life, and 29.7% were offered a management choice. Oncologists checked patient understanding in only 10.2% of consultations. Although greater information disclosure did not seem to elevate anxiety levels, greater patient participation in the decision-making process was associated with increased anxiety levels (P =.0005), which persisted over a 2-week time span.

CONCLUSION

Most patients were well informed, but important gaps remain, especially concerning information about prognosis and alternatives to anticancer treatment. These gaps invite the question concerning whether patients are led toward anticancer treatment.

Familiar drugs may prevent cancer

Despite positive results in large scale chemoprevention trials, many physicians are unaware of the potential cancer preventive properties of drugs in common usage. The antioestrogen tamoxifen and the selective cyclo-oxygenase-2 inhibitor celecoxib have been licensed in the USA for the chemoprevention of breast and colorectal cancers respectively in selected high risk individuals. Similarly, folate and retinol have been shown to decrease the incidence of colorectal cancer and squamous cell carcinoma of the skin respectively in large scale intervention trials. Other retinoids have proved efficacious in the tertiary chemoprevention of cancers of the breast and head/neck. Epidemiological evidence also exists in favour of aspirin, non-steroidal anti-inflammatory drugs, and angiotensin converting enzyme inhibitors preventing certain cancers. Phytochemicals may represent less toxic alternatives to these agents. Although some of these drugs are available without prescription and most are not yet licensed for use in cancer chemoprevention, physicians and students of medicine should be aware of this accumulating evidence base. Practitioners should be amenable to patient referral to discuss complex issues such as risk estimation or potential benefit from intervention.

A randomized controlled study of reviewer bias against an unconventional therapy

A study was designed to test the hypothesis that experts who review papers for publication are prejudiced against an unconventional form of therapy. Two versions were produced (A and B) of a 'short report' that related to treatments of obesity, identical except for the nature of the intervention. Version A related to an orthodox treatment, version B to an unconventional treatment. 398 reviewers were randomized to receive one or the other version for peer review. The primary outcomes were the reviewers' rating of 'importance' on a scale of 1-5 and their verdict regarding rejection or acceptance of the paper. Reviewers were unaware that they were taking part in a study. The overall response rate was 41.7%, and 141 assessment forms were suitable for statistical evaluation. After dichotomization of the rating scale, a significant difference in favour of the orthodox version with an odds ratio of 3.01 (95% confidence interval, 1.03 to 8.25), was found. This observation mirrored that of the visual analogue scale for which the respective medians and interquartile ranges were 67% (51% to 78.5%) for version A and 57% (29.7% to 72.6%) for version B. Reviewers showed a wide range of responses to both versions of the paper, with a significant bias in favour of the orthodox version. Authors of technically good unconventional papers may therefore be at a disadvantage in the peer review process. Yet the effect is probably too small to preclude publication of their work in peer-reviewed orthodox journals.