The global burden of occupationally related low back pain: estimates from the Global Burden of Disease 2010 study.

OBJECTIVES: The study was part of the Global Burden of Disease 2010 study and aimed to quantify the burden arising from low back pain (LBP) due to occupational exposure to ergonomic risk factors. METHODS: Exposure prevalence was based on occupation distribution; estimates of relative risk came from a meta-analysis of relevant published literature. The work-related burden was estimated as disability-adjusted life years (DALYs). Estimates were made for each of 21 world regions and 187 countries, separately for 1990 and 2010 using consistent methods. RESULTS: Worldwide, LBP arising from ergonomic exposures at work was estimated to cause 21.7 million DALYs in 2010. The overall population attributable fraction was 26%, varying considerably with age, sex and region. 62% of LBP DALYs were in males-the largest numbers were in persons aged 35-55 years. The highest relative risk (3.7) was in the agricultural sector. The largest number of DALYs occurred in East Asia and South Asia, but on a per capita basis the biggest burden was in Oceania. There was a 22% increase in overall LBP DALYs arising from occupational exposures between 1990 and 2010 due to population growth; rates dropped by 14% over the same period. CONCLUSIONS: LBP arising from ergonomic exposures at work is an important cause of disability. There is a need for improved information on exposure distributions and relative risks, particularly in developing countries.

Radiation therapy for operable breast cancer: sixty years of progress as seen through the articles published in the journal Cancer.

This review examined the 60 years of progress made in treating breast cancer from the unique perspective of the reader of Cancer, with a specific emphasis on the evolution of radiation therapy, constituting a survey of the published articles in each decade, and the standards of treatment and controversies of their times that they portray, in 3 major areas: radiation as an adjuvant therapy to mastectomy, radiation for internal mammary lymph node treatment, and radiation with breast-conserving surgery as an alternative to mastectomy.

The effect of multiple reexcisions on the risk of local recurrence after breast conserving surgery.

BACKGROUND: Guidelines for breast conserving surgery (BCS) advise mastectomy if negative margins cannot be obtained after reasonable surgical attempts. This study examined the effect of multiple reexcisions on local recurrence (LR) and identified factors predictive of the need for multiple reexcisions. METHODS: 2,770 patients undergoing BCS over 25 years were analyzed; 137 patients (group A) with two or more reexcisions, 1514 patients with one reexcision (group B), and 1119 patients who had no reexcision (group C). The median follow-up was 73 months. RESULTS: The five and ten-year actuarial LR rates for groups A, B, and C were 5.5%, 1.9%, 2.5%, and 10%, 5.7%, and 5.6%, respectively. The number of reexcisions did not predict for LR on multivariate analysis. Women <40 years underwent reexcision more frequently than other age groups. Patients with tumors detected by palpation alone made up 14% of the reexcision group versus 8% of the no reexcision group (p < 0.001). Patients with ductal carcinoma in situ and lobular carcinoma were more likely to require reexcision than those with ductal carcinoma. On multivariate analysis, younger age, detection by physical exam only, lobular histology, smaller tumor size, and the presence of extensive intraductal component (EIC) were highly significant predictors of the need for reexcision. CONCLUSIONS: Multiple reexcisions do not impact on LR rates if negative margins are ultimately obtained. Conversion to mastectomy based solely on the number of excisions performed is not indicated. Subsets of patients more likely to require reexcision, who may be candidates for a larger initial resection, can be identified.

Optimization of combined electron and photon beams for breast cancer.

Recently, intensity-modulated radiation therapy and modulated electron radiotherapy have gathered a growing interest for the treatment of breast and head and neck tumours. In this work, we carried out a study to combine electron and photon beams to achieve differential dose distributions for multiple target volumes simultaneously. A Monte Carlo based treatment planning system was investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We compared breast treatment plans generated using this home-grown optimization and dose calculation software for different treatment techniques. Five different planning techniques have been developed for this study based on a standard photon beam whole breast treatment and an electron beam tumour bed cone down. Technique 1 includes two 6 MV tangential wedged photon beams followed by an anterior boost electron field. Technique 2 includes two 6 MV tangential intensity-modulated photon beams and the same boost electron field. Technique 3 optimizes two intensity-modulated photon beams based on a boost electron field. Technique 4 optimizes two intensity-modulated photon beams and the weight of the boost electron field. Technique 5 combines two intensity-modulated photon beams with an intensity-modulated electron field. Our results show that technique 2 can reduce hot spots both in the breast and the tumour bed compared to technique 1 (dose inhomogeneity is reduced from 34% to 28% for the target). Techniques 3, 4 and 5 can deliver a more homogeneous dose distribution to the target (with dose inhomogeneities for the target of 22%, 20% and 9%, respectively). In many cases techniques 3, 4 and 5 can reduce the dose to the lung and heart. It is concluded that combined photon and electron beam therapy may be advantageous for treating breast cancer compared to conventional treatment techniques using tangential wedged photon beams followed by a boost electron field.

Clinical implementation of intensity-modulated tangential beam irradiation for breast cancer.

A Monte Carlo based intensity-modulated radiation therapy (IMRT) treatment planning system has been developed and used for breast treatment. An iterative method was used for optimization to generate IMRT plans and a step-and-shoot technique was used for beam delivery. The patient setup and incident beam directions were the same as those for conventional tangential photon treatment. The weights for the opposed beamlets in the two tangential beams were determined first by the doses at the depths of the maximum dose at both sides to minimize hot spots. The intensity of an individual beamlet pair was then optimized based on the dose at the midplane. Fine tuning was made to achieve optimal target dose uniformity and to reduce the dose to the heart when necessary. The final dose calculations were performed using the Monte Carlo method and the plans were verified by phantom measurements. The dose distributions and dose-volume-histograms of IMRT plans were compared with those of conventional plans that were generated using a commercial treatment planning system and recalculated using an in-house Monte Carlo system for the first 25 patients. The dose comparisons showed that the percentage volume receiving more than 95% of the prescription dose (V95) and the percentage volume receiving more than 100% of the prescription dose (V100) for the clinical target volume (CTV) of IMRT plans were about the same as those of conventional plans. The percentage volume receiving more than 105% of the prescription dose (V105) for the CTV was reduced from 23.1% to 7.9% on average. The percentage volume of the lung receiving more than 20 Gy dose (V20 Gy) during the entire treatment was reduced by about 10%. The percentage volume of the heart receiving more than 30 Gy dose (V30 Gy) is reduced from 3.3% to 0.3%. Further studies revealed that a less than 5 degrees change in couch angle and collimator angle at patient setup had no significant effect on the dose coverage of CTV but had significant effect on the dose to the lung and heart. The study on the effect of beam spoiler showed that it increased the dose at the buildup region by 0- 13% that varies with location. The machine output linearity and stability for small monitor unit delivery of Siemens accelerators used for this study was checked and found to be suitable for breast IMRT. The total effect of variations was calculated to be less than 1% for typical breast treatments. The beam delivery time was increased by about 2 min compared with conventional tangential treatments. The whole treatment including patient setup and beam delivery can be completed in a 15 min slot. The IMRT technique has been proven practical for breast treatment clinically. The results showed that tangential IMRT improved the dose homogeneity in the breast and reduced the dose to the lung and heart.

Recursive partitioning identifies patients at high and low risk for ipsilateral tumor recurrence after breast-conserving surgery and radiation.

PURPOSE: Recursive partitioning analysis (RPA), a method of building decision trees of significant prognostic factors for outcome, was used to determine subgroups at significantly different risk for ipsilateral breast tumor recurrence (IBTR) in early-stage breast cancer. PATIENTS AND METHODS: Nine hundred twelve women underwent breast-conserving surgery, axillary dissection, and radiation. Systemic therapy was chemotherapy with or without tamoxifen in 32%, tamoxifen in 27%, or none in 41%. RPA was used to create a decision tree according to predictive variables that classify patients by IBTR risk, and the Kaplan-Meier method was used to calculate 10-year risks. Median follow-up was 5.9 years. RESULTS: Age was the first split in the partition tree. Patients more than 55 years old had a 4% 10-year IBTR, the only further division being use of tamoxifen or not (2% v 5%, P =.03). For patients

The visual analog scale for pain: clinical significance in postoperative patients.

BACKGROUND: The visual analog scale is widely used in research studies, but its connection with clinical experience outside the research setting and the best way to administer the VAS forms are not well established. This study defines changes in dosing of intravenous patient-controlled analgesia as a clinically relevant outcome and compares it with VAS measures of postoperative pain. METHODS: Visual analog scale measurements were obtained from 150 patients on the morning after intraabdominal surgery. On the same afternoon, 50 of the patients provided a VAS score on the same form used in the morning, 50 on a new form, and 50 were not asked for a second VAS measurement. RESULTS: Visual analog scale values and changes in value were similar for patients who were given a new VAS form in the afternoon and those who used the form that showed the morning value. The proportions of patients requesting additional analgesia were 4, 43, and 80%, corresponding to afternoon VAS scores of 30 or less, 31-70, and greater than 70, respectively. Change from morning VAS score had no apparent influence on patient-controlled analgesic dosing for patients with afternoon values of 30 or less or greater than 70, but changes in VAS scores of at least 10 did discriminate among patients whose afternoon values were between 31 and 70. CONCLUSIONS: When pain is an outcome measure in research studies, grouping final VAS scores into a small number of categories provides greater clinical relevance for comparisons than using the full spectrum of measured values or changes in value. Seeing an earlier VAS form has no apparent influence on later values.

Second cancers after conservative surgery and radiation for stages I-II breast cancer: identifying a subset of women at increased risk.

PURPOSE: To assess the risk and patterns of second malignancy in a group of women treated with conservative surgery and radiation in a relatively contemporary manner for early-stage invasive breast cancer, and to identify a subgroup of these women at increased risk for a second cancer. METHODS AND MATERIALS: From 1978 to 1994, 1,253 women with unilateral Stage I-II breast cancer underwent wide excision, axillary dissection, and radiation. The median follow-up was 8.9 years, with 446 patients followed for >or= 10 years. The median age was 55 years. Sixty-eight percent had T1 tumors and 74% were axillary-node negative. Radiation was directed to the breast only in 78%. Adjuvant therapy consisted of chemotherapy in 19%, tamoxifen in 19%, and both in 8%. Factors analyzed for their association with the cumulative incidence of all second malignancies, contralateral breast cancer, and non-breast cancer malignancy were: age, menopausal status, race, family history, obesity, smoking, tumor size, location, histology, pathologic nodal status, region(s) treated with radiation, and the use and type of adjuvant therapy. RESULTS: One hundred seventy-six women developed a second malignancy (87 contralateral breast cancers at a median interval of 5.8 years, and 98 non-breast cancer malignancies at a median interval of 7.2 years). Nine women had both a contralateral breast cancer and non-breast cancer second malignancy. The 5- and 10-year cumulative incidences of a second malignancy were 5% and 16% for all cancers, 3% and 7% for contralateral breast cancer, 3% and 8%, for all second non-breast cancer malignancies, and 1% and 5%, respectively, for second non-breast cancer malignancies, excluding skin cancers. Patient age was a significant factor for contralateral breast cancer and non-breast cancer second malignancy. Young age was associated with an increased risk of contralateral breast cancer, while older age was associated with an increased the risk of a second non-breast cancer second malignancy. A positive family history increased the risk of contralateral breast cancer, but not non-breast cancer malignancies. The risk of a contralateral breast cancer increased as the number of affected relatives increased. Tamoxifen resulted in a nonsignificant decrease in contralateral breast cancer and an increase in non-breast cancer second malignancies. The 5-and 10-year cumulative incidences for leukemia and lung cancer were 0.08% and 0.2%, and 0.8% and 1%, respectively. There was no significant effect of chemotherapy or the regions treated with radiation on contralateral breast cancer or non-breast cancer second malignancy. The most common types of second non-breast cancer malignancies were skin cancers, followed by gynecologic malignancies (endometrial), and gastrointestinal malignancies (colorectal and pancreas). CONCLUSION: The 10-years cumulative incidence of a second cancer in this study was 16%. Young age and family history predicted for an increased risk of contralateral breast cancer, and older age predicted for an increased risk of non-breast cancer malignancy. The majority of patients treated with conservative surgery and radiation with or without adjuvant systemic therapy will not develop a second cancer. Long-term follow-up is important to document the risk and patterns of second cancer, and knowledge of this risk and the patterns will influence surveillance and prevention strategies.

To move or not to move: measurements of prostate motion by urethrography using MRI.

PURPOSE: Urethrography is commonly used to aid in definition of the prostate apex during CT simulation for prostate cancer. If the position of the prostate were altered by the urethrogram itself, then systematic error could be introduced into the patient's treatment. Sagittal MRI scans were acquired immediately before and after a localization urethrogram to determine the extent of displacement. METHODS AND MATERIALS: Thirteen patients underwent sagittal T2-weighted fast spin echo MRI scans. Patients were scanned supine in an alpha cradle cast in the treatment position. The prostate was contoured by 3 different observers to determine the apex location on the central sagittal MRI section and the center of mass relative to an immobile bony landmark. Statistical multivariate analysis was performed to establish if there was a net displacement of the prostate (systematic error), and to determine the margin required to cover the random prostate position within a 95% confidence interval. RESULTS: There was no significant systematic motion of either the prostate nor its apex in either the anterior-posterior or superior-inferior directions. The average motion of the prostate center of mass was 0.04 +/- 0.40 cm (1 SD) and 0.01 +/- 0.33 cm in the anterior-posterior and superior-inferior direction, respectively. The corresponding figures for location of the apex were 0.05 +/- 0.30 cm and 0.01 +/- 0.33 cm, respectively. The statistical analysis revealed that a margin of 2 mm is sufficient to cover any random motion of the prostate that could occur as a result of the urethrogram 95% of the time. CONCLUSION: Urethrography during CT simulation for prostate cancer does not cause significant prostate displacement or systematic error in planning and delivering external-beam radiation.

Lobular carcinoma in situ increases the risk of local recurrence in selected patients with stages I and II breast carcinoma treated with conservative surgery and radiation.

BACKGROUND: Lobular carcinoma in situ (LCIS) is a known risk factor for the development of invasive breast carcinoma. However, little is known regarding the impact of LCIS in association with an invasive carcinoma on the risk of an ipsilateral breast tumor recurrence (IBTR) in patients who are treated with conservative surgery (CS) and radiation therapy (RT). The purpose of this study was to examine the influence of LCIS on the local recurrence rate in patients with early stage breast carcinoma after breast-conserving therapy. METHODS: Between 1979 and 1995, 1274 patients with Stage I or Stage II invasive breast carcinoma were treated with CS and RT. The median follow-up time was 6.3 years. RESULTS: LCIS was present in 65 of 1274 patients (5%) in the study population. LCIS was more likely to be associated with an invasive lobular carcinoma (30 of 59 patients; 51%) than with invasive ductal carcinoma (26 of 1125 patients; 2%). Ipsilateral breast tumor recurrence (IBTR) occurred in 57 of 1209 patients (5%) without LCIS compared with 10 of 65 patients (15%) with LCIS (P = 0.001). The 10-year cumulative incidence rate of IBTR was 6% in women without LCIS compared with 29% in women with LCIS (P = 0.0003). In both groups, the majority of recurrences were invasive. The 10-year cumulative incidence rate of IBTR in patients who received tamoxifen was 8% when LCIS was present compared with 6% when LCIS was absent (P = 0.46). Subsets of patients in which the presence of LCIS was associated with an increased risk of breast recurrence included tumor size < 2 cm (T1), age < 50 years, invasive ductal carcinoma, negative lymph node status, and the absence of any adjuvant systemic treatment (chemotherapy or hormonal therapy) (P < 0.001). LCIS margin status, invasive lobular carcinoma histology, T2 tumor size, and positive axillary lymph nodes were not associated with an increased risk of breast recurrence in these women. CONCLUSIONS: The authors conclude that the presence of LCIS significantly increases the risk of an ipsilateral breast tumor recurrence in certain subsets of patients who are treated with breast-conserving therapy. The risk of local recurrence appears to be modified by the use of tamoxifen. Further studies are needed to address this issue.

Effect of preoperative chemoradiotherapy on surgical margin status of resected adenocarcinoma of the head of the pancreas.

We examined the effect of preoperative chemoradiotherapy on the ability to obtain pathologically negative resection margins in patients undergoing pancreaticoduodenectomy for adenocarcinoma of the head of the pancreas. Between 1987 and 2000, 100 patients underwent Whipple resection with curative intent for primary adenocarcinoma of the head of the pancreas. Pathologic assessment of six margins (proximal and distal superior mesenteric artery, proximal and distal superior mesenteric vein, pancreas, retroperitoneum, common bile duct, and hepatic artery) was undertaken by either frozen section (pancreas and common duct) or permanent section. A margin was considered positive if tumor was present less than 1 mm from the inked specimen. Margins noted to be positive on frozen section were resected whenever possible. Of the 100 patients treated, 47 (47%) underwent postoperative radiation and chemotherapy (group I) and 53 (53%) received preoperative chemoradiotherapy (group II) with either 5-fluorouracil (32 patients) or gemcitabine (21 patients). Patient demographics and operative parameters were similar in the two groups, with the exception of preoperative tumor size (CT scan), which was greater in group II (P < 0.001), and number of previous operations, which was greater in group II (P < 0.0001). Statistical analysis of the number of negative surgical margins clear of tumor was performed using Fisher's exact test. All patients (100%) had six margins assessed for microscopic involvement with tumor. In the preoperative therapy group, 5 (7.5%) of 53 patients had more than one positive margin, whereas 21 (44.7%) of 47 patients without preoperative therapy had more than one margin with disease extension (P < 0.001). Additionally, only 11 (25.6%) of the 47 patients without preoperative therapy had six negative margins vs. 27 (50.9%) of 53 in the group receiving preoperative therapy (P = 0.013). Survival analysis reveals a significant increase in survival in margin-negative patients (P = 0.02). Similarly, a strong trend toward improved disease-free and overall survival is seen in patients with a single positive margin vs. multiple margins. Overall, we find a negative impact on survival with an increasing number of positive margins (P = 0.025, hazard ratio 1.3). When stratified for individual margin status, survival was decreased in patients with positive superior mesenteric artery (P = 0.06) and vein (P = 0.04) margins. However, this has not yet resulted in a significant increase in disease-free or overall survival for patients receiving preoperative therapy (P = 0.07).

Trimodality therapy for advanced gallbladder cancer.

We conducted a retrospective review of all patients who underwent surgical extirpation for stage III, stage IV, or recurrent carcinoma of the gallbladder. Between 1991 and 1999 ten patients underwent surgical resection for advanced gallbladder cancer. All patients received adjuvant therapy either pre- or postoperatively. Radiotherapy was used in all patients and chemotherapy in 90 per cent of patients. Two patients subsequently underwent resection for locally recurrent disease. An additional patient with stage II disease initially was also treated surgically for a local recurrence. Surgical management involved cholecystectomy and resection of various amounts of liver surrounding the gallbladder bed and regional lymphadenectomy. Contiguously involved structures were resected en bloc. Resection of recurrent disease included excision of all gross tumor. The median overall survival excluding the one 30-day mortality was 53.6 months (range 8-73 months). Four patients have survived 4 or more years, and currently four patients are alive and disease free at 73, 49, 33, and 8 months. Median disease-free interval after each resection of recurrent disease was 13.8 months (range 4-28 months). We conclude that trimodality therapy in selected patients with stage III, IV, or recurrent carcinoma of the gallbladder is possible and may result in prolonged survival.

Esthetic post-and-core treatment.

The dilemma that confronts the practitioner in the area of post-endodontic rehabilitation is a positive one. The variety of products and techniques available offer practical solutions to most restorative problems. Patients have benefited [figure: see text] from recent developments in post-and-core technology, and continue to reap the benefits of research and development. The ideal system of products for the endodontic-restorative continuum includes: an esthetic resin fiber post a composite core an automixed resin luting cement current techniques that combine the automixed resin luting cement and composite core into the same component.

Local recurrence after mastectomy or breast-conserving surgery and radiation.

Approximately 10% to 15% of patients with stage I/II invasive breast cancer will develop a clinically isolated local recurrence. The standard management of an ipsilateral breast tumor recurrence following breast-conserving surgery and radiation is salvage mastectomy, while local excision and radiation are optimal treatment of a chest wall recurrence following initial mastectomy. Although there are few data regarding the efficacy of systemic therapy after isolated local relapse, chemotherapy and/or hormonal therapy should be considered for most patients because of the high risk of subsequent distant relapse. However, local relapse does not always herald distant metastases. A prolonged interval between initial treatment and local recurrence is the most important prognostic factor for subsequent outcome, and when combined with other favorable characteristics, can predict 5-year survival rates of 70% or higher.

Randomized phase III study comparing Best Supportive Care to Biafine as a prophylactic agent for radiation-induced skin toxicity for women undergoing breast irradiation: Radiation Therapy Oncology Group (RTOG) 97-13.

PURPOSE: To determine if Biafine compared to Best Supportive Care (BSC) is effective in minimizing or preventing radiation-induced dermatitis in women undergoing breast irradiation. METHODS AND MATERIALS: Patients were randomized between Biafine (n = 83) vs. BSC (n = 89). The institutions identified preference for BSC at the time of randomization. A no-treatment arm was allowed (16% received no treatment). Patients were instructed to apply randomized product three times a day, but not within 4 h of their daily RT session. Application began following their first radiation treatment and continued 2 weeks postradiation. Skin dermatitis was scored weekly utilizing the RTOG and ONS (Oncology Nursing Society) skin toxicity scales, a weekly patient satisfaction and quality-of-life questionnaire. RESULTS: Using the RTOG toxicity scale there was no overall difference for maximum dermatitis during RT between Biafine and BSC (p = 0.77). There was no difference in maximum toxicity by arm or breast size. There was an interaction between breast size and toxicity, with large-breasted women exhibiting more toxicity. Large-breasted women receiving Biafine were more likely to have no toxicity 6 weeks post RT. CONCLUSION: There was no overall difference between BSC and Biafine in the prevention, time to, or duration of radiation-induced dermatitis.