Survival Statistics For Patients Research Articles

Period analysis for ‘up-to-date’ cancer survival data: theory, empirical evaluation, computational realisation and applications

Long-term survival rates are the most commonly used outcome measures for patients with cancer. However, traditional long-term survival statistics, which are derived by cohort-based types of analysis, essentially reflect the survival expectations of patients diagnosed many years ago. They are therefore often severely outdated at the time they become available. A couple of years ago, a new method of survival analysis, denoted period analysis, has been introduced to derive more ‘up-to-date’ estimates of long-term survival rates. We give a comprehensive review of the new methodology, its statistical background, empirical evaluation, computational realisation and applications. We conclude that period analysis is a powerful tool to provide more ‘up-to-date’ cancer survival rates. More widespread use by cancer registries should help to increase the use of cancer survival statistics for patients, clinicians, and public health authorities.

Avaliação das condições de atendimento do Programa de Saúde do Adolescente no Município do Rio de Janeiro

Statistical methods known as survival analyses are useful for analyzing time-related events, in which time from a benchmark event to an endpoint is the focus of interest. Survival analysis describes not only patient survival statistics (as suggested by the name), but also other dichotomous outcomes such as time of remission, time of breastfeeding, etc. This paper discusses survival analysis techniques, commenting and comparing their utilization, especially in the field of oncology. It also presents and discusses types of epidemiological studies and data sources to which this type of analysis is applied. The authors take into account the difference between hospital-based or clinical series and population-based approaches. Interpretation of results is also discussed.

Patterns of serum CEA fall after hepatic arterial chemotherapy as sole therapy and combined with cryotherapy for colorectal metastases.

Hepatic artery chemotherapy (HAC) and cryoablation are treatments for unresectable liver metastases from colorectal carcinomas. Our centre has previously published data that describe survival statistics of patients after each of these treatments. It has also been established that serial serum carcinoembryonic antigen (CEA) concentrations may be used to monitor disease progress, and that the magnitude of fall is prognostic for both treatments. The pattern of fall of CEA following cryotherapy and regional chemotherapy has not previously been compared. In this study, we examined 26 HAC patients and 24 cryotherapy patients. The mean percentage of the pre-treatment CEA concentration for the HAC group was 60.5% at 50 days and 29.4% at 150 days, and for the cryotherapy group 24.9% at 50 days and 24.3% at 150 days. Calculating the difference between means revealed a significantly different mean fall in the cryotherapy group at 50 days (P < 0.001) and a difference in mean fall at 150 days (P > 0.1) which was not significant. In patients who responded to hepatic artery chemotherapy, the eventual CEA fall was very similar in magnitude. The pattern of fall of CEA differs in these two treatments.

Orthopedic surgical management of skeletal complications of malignancy.

Coincident with improved overall cancer palliation during the past 2 decades has been an increasing incidence of clinically apparent bone metastases, and from these metastases subsequent pathologic fractures of the long bones, spine, and pelvis. Current techniques for surgical management of these fractures are extremely effective in alleviating pain and allowing patients to resume an ambulatory status, often without the need of external support. This, in turn, has significantly improved the quality of the remaining months or years of these individuals' lives. In fact, the long term survival of patients after their first long bone pathologic fracture from malignancy has more than tripled for the most common cancers (breast carcinoma, prostate carcinoma, lymphomas, and myelomas) during the past 25 years. Surgical techniques for stabilizing pathologic or impending fractures must be individualized for the area of involvement, the particular qualities of the bone involved, and the potential for involvement of adjacent soft tissue structures. Long bone fractures most commonly occur in the femur and humerus and are typically internally fixed by intramedullary devices that control impaction, distraction, and torquing stresses by the use of proximal and distal interlocking fixation. Such fixation must be able to withstand weight-bearing stresses on lower extremity long bones. Upper extremity pathologic fractures are often subjected to distractive forces inherent in lifting and pulling, but they are also subjected to heavy compressive forces, particularly in patients who require crutches or other devices to assist them in walking. Fixation of upper or lower extremity long bone fractures ordinarily may be accomplished with minimal blood loss or morbidity. In contrast, fractures or impending fractures involving the acetabulum necessitate extensive joint reconstruction, with inherent increased potential for morbidity and complications. For this reason, the anticipated prognosis for survival and mobility should be greater preoperatively for patients with acetabular fractures than for patients with fractures of either upper or lower extremity long bones. Most spinal metastases can be managed conservatively. Those requiring surgical intervention present with progressive neurologic compromise, which requires decompression, or spinal instability, which requires stabilization. Constructs for internal stabilization of the spine must not be adversely affected by local postoperative irradiation. Ninety-six percent of patients experience good or excellent relief of pain after internal fixation of pathologic malignant long bone fractures. Eighty-four percent of patients with acetabular fractures experience good or excellent relief of pain after joint reconstruction. Eighty-two percent of patients with neurologic compromise secondary to vertebral malignancy improve at least one functional grade after decompression and stabilization, and 88% experience good or excellent relief of spinal pain with restoration of walking ability. Thirty-two percent survived for more than 2 years after spinal decompression and stabilization. Patients with pathologic fractures from metastatic carcinoma of the breast had a mean survival of 24.6 months after surgical management of their fractures. There was a similarly encouraging improvement in the survival statistics for patients with other primary tumor types. Most malignant pathologic fractures of the pelvis, long bones, or spine are amenable to effective stabilization by the techniques described in this article. These techniques allow resumption of weight-bearing ambulation in all but a few patients, good or excellent relief of pain in the vast majority, and an enhanced anticipation of survival and improvement in quality of life.

Editorial on “occult cervical nodal metastases in esophageal cancer: Preliminary results of three-field lymphadenectomy”

Editorial on “occult cervical nodal metastases in esophageal cancer: Preliminary results of three-field lymphadenectomy”

Reconstructive Considerations for Limb Salvage Surgery

Tumors in the musculoskeletal system are generally treated surgically, although radiation therapy and chemotherapy have greatly improved survival statistics of patients with high-grade sarcomas of the musculoskeletal system. The mainstay in treatment of nearly every primary tumor of the musculoskeletal system is surgical resection for cure. Radiation therapy and chemotherapy continue to be important adjuvants in the overall management of musculoskeletal tumors. Functional limb salvage following radical resection is now possible in most resectable cases by placement of an alloplastic prosthesis, homograft, or autogenous bone for skeletal reconstitution, followed by well-vascularized soft-tissue coverage.

SURGICAL RESECTION OF LUNG CANCER

Surgery remains the treatment of choice for patients with lung cancer who demonstrate resectable tumors. The type of surgical procedure performed depends on the degree of metastasis and the functional lung capacity of the patient. In addition to problems common to all surgical patients, complications such as cardiac arrhythmias, pulmonary embolus, respiratory failure, bronchopleural fistula, and empyema may occur. Although survival statistics for patients with lung cancer remain poor, the common denominator in patients that have survived 5 years is surgical resection.

A deterministic approach to survival statistics

Survival functions of the form p(t) = exp[-(lambda t) gamma], gamma greater than 0 can be generated by deterministic nonlinear, asymptotically stable (chaotic) dynamical systems. These systems thus provide an alternative to stochastic interpretations of failure time data. We use this approach to analyze cancer patient survival statistics. In this manner we are able to obtain fresh insights into the implications of negative and positive clinical trials.

Survival with carcinoma arising in mucosal ulcerative colitis.

Adenocarcinoma of the colon is a well-recognized complication of total chronic ulcerative colitis. The incidence increases with time, and the carcinoma arising in chronic ulcerative colitis has developed a bad clinical reputation in terms of aggressive behavior. The survival statistics of patients with cancer arising in chronic ulcerative colitis are compared with statistics for a group of noncolitic patients with equivalent clinicopathologic staging treated at the same institution. When grouped by extended Duke's classification and compared with carcinoma arising without ulcerative colitis, there was no statistical difference in survival rates. The overall results are worse because of a higher percentage of patients with incurable disease at the time of operation. With improved surveillance and methods of detecting premalignant changes, the necessity for prophylactic proctocolectomy should decline.

Phagocyte strategy vs. microbial tactics.

We are constantly in contact with a vast array of microorganisms living in our external environment as well as on our own mucosal surfaces. The overwhelming majority of these organisms are nonpathogenic, only a relative few being virulent for humans. Nonetheless, our survival in this sea of microbes depends largely on the ability of phagocytic cells to seek out and destroy these organisms. The importance of phagocytic cells is amply illustrated by the high rates of infection and dismal survival statistics for patients who are severely neutropenic for prolonged periods. Since phagocytic cells are motile, are capable of ingesting microbial organisms, and possess specialized mechanisms for killing ingested organisms, they are well suited to their protective role. However, it is naive to assume that microbes passively accept their fate at the hands of phagocytes. In fact, it appears that for every step in the normal phagocytic response to infection, a mechanism exists by which microorganisms can avoid or neutralize the injurious consequences of their encounters with phagocytes. The tactics that different organisms employ to counter phagocytic strategy are the topic of this paper. Microbial interactions with phagocytic cells have been the subject of several recent reviews [1-3] and a conference [4]. The important role that the microbial surface plays in this interaction has also received appropriate emphasis [5, 6]. A knowledge of the physiology of phagocytic

Natural history of aortic and mitral valve disease

An appreciation of the natural history of acquired valvular heart disease is a prerequisite to an understanding of how surgical intervention has altered the natural outlook. The prognosis for a patient with valvular heart disease treated medically is dependent on the stage of the disease at which he is first seen. Therefore, assessment for surgery requires evaluation of the pathophysiologic consequences that have resulted from the hemodynamic alterations. Survival statistics for patients seen at the University of California Medical Center at San Francisco are presented and compared with the data of others. Stenotic lesions appear to have a poorer prognosis than chronic regurgitant lesions and generally warrant surgical intervention at an earlier functional stage of the disease. However, valvular insufficiency produced acutely is poorly tolerated and may constitute a surgical emergency.