[Urachal cancers]

Web-Based Prediction Models for Overall Survival and Cancer-Specific Survival of Patients With Primary Urachal Carcinoma: A Study Based on SEER Database

Objective:

We aimed to establish nomograms to predict the overall survival (OS) and cancer-specific survival (CSS) of patients with primary urachal carcinoma (UrC).

Methods

Information on patients diagnosed with UrC from 1975 to 2018 was collected from the Surveillance, Epidemiology, and End Results (SEER) Program Research Data. The independent prognostic factors were determined using univariate and multivariate Cox regression. Backward variable elimination according to the Akaike information criterion (AIC) identified the most accurate and parsimonious model. Nomograms were built based on regression coefficients. The C-index, calibration plot, Brier score, integrated discrimination improvement (IDI), area under the receiver operating curve (AUC), and decision curve analysis (DCA) curve were used to evaluate the efficiency of models.

Results

In total, 236 patients obtained from SEER were divided randomly into training and validation cohorts in a 70:30 ratio (166 and 70 patients, respectively). In the training cohort, multivariate Cox regression analysis indicated that pTNM/Sheldon/Mayo staging systems (included respectively), age, and tumor grade were independent prognostic factors for OS. A similar result was also found in CSS. While other variables, such as radiotherapy and chemotherapy, did not identify significant correlations. In predicting OS and CSS at 3- and 5- years, the nomograms based on pTNM showed superior discriminative and calibration capabilities in comparison to multiple statistical tools. The C-index values for the training cohort were 0.770 for OS and 0.806 for CSS, and similar outcomes were shown in further internal validation (C-index 0.693 for OS and 0.719 for CSS). We also discovered that the link between age at diagnosis and survival follows a U-shaped curve, indicating that the risk of poor prognosis decreases first and then increases with age.

Conclusion

The efficacy of pTNM in predicting the prognosis of patients with UrC was greater than that of the Sheldon and Mayo staging system. Therefore, we recommend pTNM as the preferred system to stage UrC. The novel constructed nomograms based on pTNM, age, and tumor grade showed high accuracy and specificity and could be applied clinically to predict the prognosis of patients with UrC.

U-shaped relationship of age at diagnosis and cancer-specific mortality in primary urachal adenocarcinoma: a cohort study

BACKGROUND

To examine the association between age at diagnosis and cancer-specific mortality (CSM) in primary urachal adenocarcinoma.

METHODS

The data was obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results program (SEER). A total of 393 patients were included in the study. Smooth curve fitting and two-piecewise Cox proportional hazards models were used to identify the nonlinearity between the age at initial diagnosis and cancer-specific survival rate. Survival time between different groups was compared using Kaplan-Meier survival curves and the log-rank test.

RESULTS

Using smooth curve fitting we found that the relationship between age at diagnosis and cancer-specific survival takes on a U-shaped curve. The inflection point that we identified for the age at initial diagnosis was 60 years. The log-likelihood ratio test (P<0.05) indicated that the two-piecewise Cox regression model was more appropriate for fitting the correlation of age at diagnosis and CSM. The two-piecewise Cox regression model showed that when the age was <60 years, reduced risk of CSM was significantly associated with increased age (HR: 0.95, P=0.0002). Conversely, when age was >60 years, increased risk of CSM was significantly associated with increased age (HR: 1.05, P=0.0499).

CONCLUSIONS

In summary, our study suggested that the relationship between age at diagnosis and cancer-specific survival is nonlinear, and takes on a U-shaped curve. Both younger and older age at initial diagnosis age were associated with increased CSM.

Treatment Outcome and Relevance of Palliative Chemotherapy in Urachal Cancer

BACKGROUND

Urachal cancer is a rare malignancy that accounts for <1% of bladder cancers. There is currently no consensus on the diagnosis and management of urachal cancer and there are very few reports on palliative chemotherapy for unresectable disease. We delineate the clinical features and treatment outcome of urachal cancer, in particular the relevance of palliative chemotherapy in recurrent, metastatic disease.

METHODS

The clinicopathologic variables and treatment outcome of patients who were treated for urachal cancer were retrospectively reviewed.

RESULTS

Among 28 eligible patients, 25 had localized disease and 3 had metastatic disease at initial diagnosis. All patients with localized disease underwent curative resection and there was disease recurrence in 10. Out of 13 patients with metastatic disease either at initial diagnosis or during follow-up, the lung was the most common metastatic site (n = 5), followed by the liver, bone and peritoneum. Ten patients received palliative chemotherapy. A total of 24 chemotherapeutic regimens were administered; regimens with a base of fluoropyrimidine (5-FU), taxane and gemcitabine were the most common. The overall response rate of all chemotherapeutic regimens was 16.7%. The 5-FU-based regimens showed a good response, with 2 of 4 patients who received these showing a partial response. One tumor with a partial small-cell component showed a partial response to both an etoposide-based regimen and a taxane-based regimen.

CONCLUSIONS

In urachal cancer, curative surgery is still the recommended treatment with respect to overall survival. A 5-FU-based chemotherapy regimen could be considered for metastatic recurrent disease.