Biomedical subjects

Angel Nickolov

Publications and source records attributed to Angel Nickolov.

6 recordsLinked to original sources

PubMed2006

Associations between the age at diagnosis and location of colorectal cancer and the use of alcohol and tobacco: implications for screening.

BACKGROUND: Individualizing recommendations for colorectal cancer (CRC) screening intervals and modalities requires accurate risk assessment. Although hereditary predisposition is commonly used, the effect of exogenous risk factors has remained largely unexplored. To address this, we analyzed the age at presentation and location of CRC in relation to alcohol and tobacco use. METHODS: We queried the IMPAC Medical Registry Services Cancer Information Resource File for CRCs diagnosed between June 1, 1993, and December 31, 2003. Subjects were classified as current, past, or never users of alcohol and tobacco. A logistic regression model for location of CRC and a linear regression model for age at diagnosis were constructed using these explanatory variables along with gender, race, and insurance status. RESULTS: Our data set consisted of 161 172 patients with CRC. Current drinking, smoking, and smoking plus drinking were associated with younger ages at onset of CRC (adjusted age difference, 5.2, 5.2, and 7.8 years, respectively; P<.001 for all). A distal location of CRC was more likely to occur in current drinkers (odds ratio, 1.192; 95% confidence interval, 1.15-1.23) and smokers (odds ratio, 1.164; 95% confidence interval, 1.12-1.21). Colorectal cancer in men tended to occur earlier (adjusted age difference, 1.9 years; P<.001) and have a distal predominance (odds ratio, 1.42; P<.001) compared with women. The smoking but not the drinking effect size was greater in women than in men (adjusted age difference, 2.6 years; P<.001). CONCLUSIONS: Alcohol use, tobacco use, and male gender were associated with earlier onset and a distal location of CRC. If confirmed, these factors should guide recommendations regarding initiation of CRC screening and, possibly, choice of techniques.

Age Distribution↗

PubMed2006

Effect of parity on sexual function: an identical twin study.

OBJECTIVE: To assess the impact of childbirth on female sexual function by using an identical twin study design. METHODS: A survey including the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12) was administered to 542 twin sisters, and PISQ-12 scores of 29 twin pairs discordant for parity were compared. Multiple linear regression models were used to evaluate impact on total PISQ-12 scores in 276 identical, sexually active twins. Three models were used 1) to evaluate the effect of parity and general risk factors, 2) to examine the impact of birth mode, and 3) to examine the role of episiotomy and operative delivery. RESULTS: Mean PISQ-12 scores were significantly higher for discordant nulliparous twins than for parous twins (102.5 versus 93.5, P < .001). The mean (standard deviation) PISQ-12 score was 99.3 (11.7). Age of 50 years or older (difference in mean scores -5.4, P = .019), stress urinary incontinence (-3.3, P = .02), urge urinary incontinence (-5.9, P < .001), parity (-6.5, P < .001), and fecal incontinence (-5.7, P = .048) were associated with decreased mean PISQ scores in the univariable analysis. Parity (-4.9, P < .001) and urge urinary incontinence (-4.3, P = .009) were the only factors remaining independently predictive of diminished sexual function in the multivariable analysis. Mode of delivery did not significantly affect mean PISQ scores (P = .763). Among women who had vaginal deliveries only, neither episiotomy nor operative delivery was associated with change in PISQ scores (P = .553). CONCLUSION: Nulliparous women reported superior sexual satisfaction scores compared with parous women, regardless of age and mode of delivery. Childbirth appears to have a lasting impact on sexual function, due to psychological more than physical factors, well beyond the postpartum period. LEVEL OF EVIDENCE: II-2.

Adult↗

PubMed2005

Delivery mode is a major environmental determinant of stress urinary incontinence: results of the Evanston-Northwestern Twin Sisters Study.

OBJECTIVE: We studied a large cohort of identical twin sisters, utilizing the unique properties of a twin research design to explore the relationship between obstetrical delivery mode and stress urinary incontinence. STUDY DESIGN: An anonymous 67-item survey was completed by 271 identical twin pairs (n = 542) at the world's largest annual gathering of twins. Logistic regression for repeated binary measures was used to evaluate risk factors and accounting for shared genetics within pairs. RESULTS: The twins had a mean age of 47.1 years (range 15 to 85 years), and stress urinary incontinence was reported by 51.8%. Stress urinary incontinence was associated with age (P = .001), parity (P = .001), obesity (P = .002), and birth mode, with vaginal delivery conferring a considerable increase in stress urinary incontinence risk relative to cesarean section (odds ratio 2.28, 95% confidence interval 1.14 to 4.55, P = .019). CONCLUSION: Vaginal delivery mode represents a potent determinant of stress urinary incontinence, carrying more than twice the risk of cesarean section. This study of identical twins provides new insight into the epidemiology of female incontinence.

Adolescent↗

PubMed2005

Risk factors for female anal incontinence: new insight through the Evanston-Northwestern twin sisters study.

OBJECTIVE: To evaluate risk factors for anal incontinence using an identical twin sisters study design to provide control over genetic variance. METHODS: A total of 271 identical twin sister pairs (mean age 47 years) completed the validated Colorectal Anal Distress Inventory questionnaire detailing the presence and severity of anal incontinence. Data were analyzed using a stepwise logistic regression with repeated binary measures to account for correlated data within twin pairs. Three different statistical models were used to analyze nonobstetric as well as obstetric risk factors separately. RESULTS: Significant risk factors for anal incontinence and higher Colorectal Anal Distress Inventory anal incontinence subscale scores included age 40 years or older (fecal: odds ratio [OR] 2.82, 95% confidence interval [CI] 1.21-6.0; flatal: OR 1.90, 95% CI 1.11-3.24), menopause (fecal: OR 2.10, 95% CI 1.15-3.8; flatal: OR 2.11, 95% CI 1.43-3.13), increasing parity (parity > or = 2; fecal: OR 3.09, 95% CI 1.25-7.65; flatal: OR 2.72, 95% CI 1.65-4.51), and the presence of stress urinary incontinence (fecal: OR 2.11, 95% CI 1.12-3.98; flatal: OR 1.72, 95% CI 1.14-2.59). Obesity was associated with significantly higher Colorectal Anal Distress Inventory anal incontinence subscale scores (mean difference 5.18, P = .007). Cesarean delivery after initiation of labor was associated with a lower prevalence of anal incontinence than vaginal birth; however, this difference was not statistically significant (17% compared with 4%, P = .11). No anal incontinence was noted in women who had only elective cesarean deliveries. CONCLUSION: Age, menopause, obesity, parity, and stress urinary incontinence are the major risk factors for female anal incontinence.

Adult↗

PubMed2004

Axillary recurrence after sentinel node biopsy.

BACKGROUND: Sentinel node biopsy (SNB) has evolved as the standard of care in the surgical staging of breast cancer. This technique is accurate for surgical staging of axillary nodal disease. We hypothesized that axillary recurrence after SNB is rare and that SNB may provide regional control in patients with microscopic nodal involvement. METHODS: With institutional review board approval, SNB was performed with peritumoral injection of 99mTc-labeled sulfur colloid. From 1996 to 2003, 1167 patients were entered into a prospective cancer database after surgical therapy; 916 patients consented to long-term follow-up. Fifty-two patients (5.7%) did not map successfully and were excluded, leading to a study population of 864 patients. The median follow-up was 27.4 months (range, 1-98 months). RESULTS: The median number of sentinel nodes harvested was 2, and 633 (73%) patients had negative sentinel nodes. Thirty (4.7%) of those sentinel node-negative patients underwent completion axillary dissection, whereas 592 (94%) patients were followed up with observation. A total of 231 (27%) had positive sentinel nodes: 158 (68%) of these patients underwent completion axillary dissection, and 73 (32%) were managed with observation alone. Two (.32%) patients who were sentinel node negative had an axillary recurrence; one of these patients had undergone completion axillary dissection. No patient in the observed sentinel node-positive group had an axillary recurrence (odds ratio, .37; P = .725). CONCLUSIONS: On the basis of a median follow-up of 27.4 months, axillary recurrence after SNB is extraordinarily rare regardless of nodal involvement, thus indicating that this technique provides an accurate measure of axillary disease and may impart regional control for patients with node-positive disease.

Axilla↗

PubMed2004

Failure of sentinel lymph node mapping in patients with breast cancer.

BACKGROUND: Lymphatic mapping with sentinel lymphadenectomy (SL) has become more widely used as an alternative to axillary dissection for the staging of breast cancer. This study was conducted to evaluate the potential associations of patient and tumor characteristics with the lymphatic mapping failure rate. STUDY DESIGN: Between September 1996 and April 2003, 1,094 breast cancer patients participated in a single-institution prospective SL protocol, which was conducted using technetium 99 m sulfur colloid alone to identify sentinel lymph nodes. During the validation phase, consisting of the first 80 patients, all patients had SL followed by axillary dissection. Beginning with the 81st patient, the standard technique consisted of radiolabeled colloid injection in a peritumoral distribution 16 to 24 hours before the operation, followed by SL alone for node-negative patients. RESULTS: Of 1,094 consecutive patients, 62 (5.7%) did not map. Patients having more than 10 involved lymph nodes had a significantly higher incidence of mapping failure (40.9%) than those who were node-negative (5.3%) (odds ratio = 9.19, p = 0.002). Age was a factor predictive of mapping failure for node-negative patients 70+ years of age (odds ratio = 3.14, p = 0.018). Biopsy technique, tumor size, tumor location, cell type, and surgeon experience were not predictors of mapping failure, regardless of node status. CONCLUSIONS: The lymphatic mapping failure rate was associated with both anatomic and pathologic factors. Patients with extensive nodal involvement had a significantly greater chance of mapping failure. Among node-negative patients, those who were older were more likely to have mapping failure than those who were younger, suggesting that decreased breast density in postmenopausal women might provide an anatomic explanation for nonmapping.

Aged↗