RATES OF GROWTH OF PULMONARY METASTASES AND HOST SURVIVAL

Factors influencing growth rate of recurrent stomach cancers as determined by analysis of serum carcinoembryonic antigen

BACKGROUND

Although there are many reports regarding the growth rate of human tumors, those discussing stomach cancer are rare due to the difficulty in evaluating the growth rate of stomach cancer. Stomach cancers grow with either a large central depression or through severe invasion. Metastatic sites of stomach cancer, however, grow expandingly, as with pulmonary tumors.

METHODS

The reported doubling time estimate, based on the serum level of carcinoembryonic antigen (CEA), agreed with the actual tumor doubling time investigated in 112 previously untreated patients with recurrent gastric cancers. The influencing factors of the CEA doubling time were studied clinicopathologically, and a possible correlation between postoperative survival and the CEA doubling time was noted.

RESULTS

The CEA doubling time ranged from 12 to 105 days, with a mean of 37.5 +/- 20.5 days (mean +/- standard deviation) and a median of 32 days. The CEA doubling time did not differ significantly between sexes or between patients of varying ages. However, the CEA doubling time was significantly shorter in patients with papillary adenocarcinoma than in those with well or moderately differentiated tubular adenocarcinoma. The CEA doubling time of patients with poorly differentiated adenocarcinoma was divided into two groups--a shorter one and a longer one. The doubling time was also significantly shorter in patients with liver metastasis than in those with lymph node metastasis or peritoneal dissemination. Furthermore, among patients who did not receive any chemotherapy, a significant correlation was observed between the CEA doubling time and postoperative survival time. Most treated patients survived longer than untreated patients.

CONCLUSION

The influencing factors on growth rates in recurrent stomach cancers were histologic type and metastatic sites. This growth rate plays an important role in determining the degree of biologic malignancy and may be influenced by some chemotherapeutic regimens.

Tumor doubling time and prognostic assessment of patients with primary lung cancer

BACKGROUND

Relationships between tumor doubling time (DT) and other prognostic factors and the risk of death related to these factors are not yet fully understood.

METHODS

Tumor doubling time of primary lung carcinomas of 174 patients, detected in a limited number of local municipalities during a limited period, was calculated using the Schwartz formula. Survival rate of the 174 patients was compared with reference to categories of prognostic factors (univariate analyses) and significant factors affecting survival were identified by multivariate analyses using the Cox proportional hazard model.

RESULTS

Tumor doubling time had a log normal distribution. There was a significant difference in mean DT in relation to sex, smoking history, presence of symptoms, cell type, primary tumor factor, and stage. Univariate analyses showed a significant difference in survival in relation to DT, age, sex, method of tumor detection, smoking history, symptoms, therapy, cell type, primary tumor (T) factor, regional lymph node (N) factor, distant metastasis (M) factor, and stage. Multivariate analyses using the Cox's proportional hazard model in a stepwise fashion identified a final set of five significant variables: N factor (P = 0.0001); therapy (P = 0.0016); M factor (P = 0.0017); T factor (P = 0.0018), and DT (P = 0.0152).

CONCLUSIONS

Tumor doubling time was an independent and significant prognostic factor for lung cancer patients.

Measurement of growth rate of lung metastases in 21 patients with bone or soft-tissue sarcoma

The volume doubling time (T2) of 52 lung metastases in 21 patients was calculated from measurements done on plain chest radiographs. Follow-up times ranged from 14 to 819 days. The measurements were fairly well reproducible in the majority of patients, although considerable discrepancies in T2 estimates made by two independent observers were found in a few patients. The median doubling time was 34.9 days (estimated 95% range 3.9 to 352 days). The variation of T2:s between patients was significantly (P = 0.0001) larger than that between T2: of multiple metastases in the same patients. The growth of the metastases seemed to be well described by a simple exponential function in all patients with more than two measurements, without evidence of Gompertzian growth. There seemed to be a linear correlation between the logarithm of T2 and log-survival time from diagnosis of metastatic disease, even if only one third of the variation of survival times between patients could be explained by differences in T2. T2 was not a significant factor for survival in Cox-analysis (P = 0.10).

Accelerated growth rates of recurrent hepatocellular carcinoma after liver transplantation

The growth rates of recurrent hepatocellular carcinoma (HCC) after orthotopic liver transplantation (OLTX) were estimated by calculating the tumor doubling time (TDT) in 20 patients. The mean TDT, calculated by multiple measurement of tumor size, was 44.3 +/- 11.3 days (mean +/- standard error) in 12 patients with pulmonary metastasis (range, 10 to 161 days) and 37.6 +/- 8.9 days (range, 7 to 65 days) in 5 patients with liver allograft recurrence. The TDT as estimated by serum alpha-fetoprotein (AFP) levels in 6 patients was 37.3 +/- 10.0 days (range, 12 to 84 days). The mean TDT obtained from 5 control subjects with HCC who were treated with liver resection (without immunosuppression) was 273.8 +/- 79.1 days (range, 82 to 560 days). The disease-free period and survival time after OLTX both correlated well with the TDT (r = 0.546 and r = 0.701, respectively). The patients with fibrolamellar HCC had a greater TDT and a longer survival time than those with nonfibrolamellar HCC. Despite a wide range of TDT in patients who received transplants, their recurrent HCC tumors grew significantly faster than those of patients with the same disease who did not receive transplants. The factors involved in this accelerated growth rate may include the use of immunosuppressive drugs and the consequent suppression of host immunity against the growth of micrometastasis.

Accelerated growth rates of recurrent hepatocellular carcinoma after liver transplantation

The growth rates of recurrent hepatocellular carcinoma (HCC) after orthotopic liver transplantation (OLTX) were estimated by calculating the tumor doubling time (TDT) in 20 patients. The mean TDT, calculated by multiple measurement of tumor size, was 44.3 +/- 11.3 days (mean +/- standard error) in 12 patients with pulmonary metastasis (range, 10 to 161 days) and 37.6 +/- 8.9 days (range, 7 to 65 days) in 5 patients with liver allograft recurrence. The TDT as estimated by serum alpha-fetoprotein (AFP) levels in 6 patients was 37.3 +/- 10.0 days (range, 12 to 84 days). The mean TDT obtained from 5 control subjects with HCC who were treated with liver resection (without immunosuppression) was 273.8 +/- 79.1 days (range, 82 to 560 days). The disease-free period and survival time after OLTX both correlated well with the TDT (r = 0.546 and r = 0.701, respectively). The patients with fibrolamellar HCC had a greater TDT and a longer survival time than those with nonfibrolamellar HCC. Despite a wide range of TDT in patients who received transplants, their recurrent HCC tumors grew significantly faster than those of patients with the same disease who did not receive transplants. The factors involved in this accelerated growth rate may include the use of immunosuppressive drugs and the consequent suppression of host immunity against the growth of micrometastasis.

Influence of hepatitis B virus infection and age on mode of growth of hepatocellular carcinoma

According to the extent of hepatic involvement of the tumor and that of portal vein invasion at the time of initial diagnosis, patients with hepatocellular carcinoma (HCC) were grouped into three or four groups. Correlations among the extent of hepatic involvement, extent of portal vein invasion, and prevalence of hepatitis B surface antigen (HBsAg) and age distribution were examined. The extent of hepatic involvement of the tumor and that of portal vein invasion were significantly greater in patients with positive HBsAg compared with findings in the negative patients (P less than 0.001). For cases of both positive and negative HBsAg, patients with a more extensive HCC were significantly younger. Results of the multivariate logistic regression analysis showed that hepatitis B antigenemia and younger age were statistically significant and independent positive predictors of extensive HCC. These results strongly suggest that hepatitis B surface antigenemia and age play an important role in the growth mode and the kinetics of HCC in Japanese patients.

Is Gompertzian or exponential kinetics a valid description of individual human cancer growth?

It is generally accepted that human cancers grow in an exponential or Gompertzian manner. This assumption is based on analysis of the growth of transplantable animal tumors and on averages of tumor growth in human populations. A computer model of breast cancer in individual patients has raised some doubts about this assumption. The computer model predicts an irregular pattern of tumor growth that incorporates plateaus or dormant periods separated by Gompertzian growth spurts. Since growth patterns involving plateaus are not predicted by conventionally accepted exponential or Gompertzian kinetics, sufficient documentation of their existence may be regarded as some evidence that the computer model is correct. The literature has been surveyed to identify growth patterns specifically predicted by the model. The literature contains clinical evidence from individual patients of this growth pattern in primary breast, large intestine and rectum, and pulmonary cancers and metastatic pulmonary cancer. Much data, including the only breast data, are not consistent with exponential or Gompertzian kinetics but are explainable by irregular growth kinetics. Exponential growth is valid for some tumors and for short times, but there are many papers citing significant deviations from that growth. Exponential growth may accurately describe averages of human tumor growth and growth of multipassaged experimental tumors, but it is not valid for all individual tumors.

The growth kinetics of human tumours

Little recent work has been done on the growth kinetics of human tumours although sophisticated radiological techniques are now available. Such sequential radiological studies would provide valuable insights into the natural history of human tumours and their response to treatment.

Evaluation of the prognosis for small hepatocellular carcinoma based on tumor volume doubling time. A preliminary report

The relationship of tumor volume doubling time to length of patient survival was investigated for 15 patients with small hepatocellular carcinoma smaller than 4.5 cm in diameter. The mean tumor volume doubling time of these 15 nodules was 102 +/- 77 days (mean +/- SD; range 41 to 305 days) before the initiation of a specific treatment for cancer. These doubling times tended to correlate with mitotic indexes of the tumors and the patients could be divided into two groups according to the therapeutic modalities used. Patients in Group A received systemic chemotherapy without response or nonspecific treatments for cancer. In this group, there was a positive correlation between tumor volume doubling time and survival length (r = 0.8812; P less than 0.025). Patients in Group B either received hepatectomy after transarterial embolization or systemic chemotherapy or received hepatectomy alone. In this group, early death occurred in patients who had shorter tumor volume doubling times. Three surgically treated patients in Group B were evaluated as having survived for a significantly long period as assessed from their tumor volume doubling times. These results indicate that tumor volume doubling time is one of the determining factors of survival length in patients with hepatocellular carcinoma, and, therefore, can be used in the evaluation of therapeutic efficacy.

Proliferative potential of brain metastases

Thirteen patients with metastatic brain tumors received an intravenous infusion of bromodeoxyuridine (BUdR) 200 mg/m2 at craniotomy) to label S-phase tumor cells. Excised tumors were stained immunohistochemically for BUdR. The percentage of BUdR-positive cells was calculated to determine the BUdR labeling index (LI) (or fraction of S-phase cells), which provides an estimate of the proliferative potential. Histologically, 11 patients had adenocarcinoma (four well-differentiated, three moderately differentiated, and four poorly differentiated), one had a large cell carcinoma, and one had a small cell carcinoma. All tumors had a BUdR LI greater than 5% (mean, 13.3 +/- 7% standard deviation). Moderately and poorly differentiated adenocarcinomas had a higher LI than well-differentiated adenocarcinomas (median, 15.3% versus 8.2%). These LI values are considerably higher than those reported for primary tumors with comparable histologic features. Thus, metastatic tumors in the brain may grow faster than the primary tumors from which they originate.

Growth rate of hepatic metastases in colorectal carcinoma

The rates of growth of 29 hepatic metastases from 15 patients with primary colorectal carcinoma were studied using serial computed tomography (CT). Eleven metastases were found by the surgeon at laparotomy (overt metastases); the remaining eighteen were not evident to the surgeon at laparotomy, but were detected by CT scan during the immediate postoperative period (occult metastases). An estimate of tumour volume doubling time was obtained from a semi-logarithmic plot of tumour cell number against time. The mean doubling time for the overt metastases was 155 +/- 34 days (+/- s.e.m.) compared with 86 +/- 12 days (P less than 0.05) for the occult metastases. The age of the metastases at the time of surgery was estimated by extrapolation of the observed growth curve assuming Gompertzian kinetics. The mean age of the overt metastases was 3.7 +/- 0.9 years (+/- s.e.m.) The corresponding age of the occult metastases was 2.3 +/- 0.4 years.

Cost-effective follow-up of the cancer patient. Time for a new look

Physicians are increasingly aware of their complex responsibilities in finding the difficult compromise necessary to achieve cost-effective follow-up care of cancer patients. They must consider not only the best interests of their patients but also the interests of a cost-conscious society. To meet their new societal obligations, physicians trained solely to serve the patient's best interest must now learn how to do so at the least expense. This implies knowing both the costs and the performance characteristics of the diagnostic tests ordered in follow-up. The authors analyze this dilemma as it applies to follow-up of patients following primary treatment for colon cancer or nonseminomatous testicular cancer. Principles of cost-effective patient management are reviewed.

Growth rate of pulmonary metastases from soft tissue sarcoma

The growth rate of pulmonary metastases was analyzed in eleven patients with soft tissue sarcoma. In cases where more than two examinations were available the growth rate seemed to be exponential. In all but one case microscopic pulmonary spread was calculated to be present when the primary tumor was diagnosed. Tumor doubling time varied between 8 and 198 days in different patients. The variation in growth rate between various nodules in the same patient was much less pronounced but nevertheless considerable, which might, at least partly, be explained by tumor cell polyclonality. Computed tomography of the chest may detect pulmonary metastases earlier than conventional radiography and is therefore recommended in the preoperative work-up in soft tissue sarcoma.

Prognosis in soft tissue sarcoma

Consensus is still lacking as regards which surgical procedures carry a low risk of local recurrence in soft tissue sarcoma. A series of 81 patients with Grades I-IV soft tissue sarcomas of the locomotor system, with a minimum follow-up time of 6 years, was studied with respect to local recurrence. All the patients were operated on with wide surgical margins without adjunctive therapy. A subclassification of these margins was performed. A wide F margin, obtained by myectomy of one or several muscles, but not of the total compartment, was found to be a safe procedure, giving a local recurrence rate of less than 0.1. This applied when surgery was performed without a preceding open biopsy. For subcutaneous tumors a wide S margin, including the deep fascia, also resulted in a small local recurrence rate, even if performed after incisional biopsy or marginal surgery. More than one half of all patients with soft tissue sarcoma in the locomotor system have tumors suitable for surgical treatment with a wide F or a wide S margin for a low local recurrence risk. A wide margin where the surgical dissection had transgressed the muscle where the tumor was located or areolar tissue in cases of extramuscular tumor (wide AM margin) was found to result in a higher local recurrence rate, around 0.25. There is no generally accepted staging system for soft tissue sarcomas. Those systems in most common use were not constructed after statistical multivariate analysis, whereby the strongest prognostic factors may be identified. The staging system of the American Joint Committee (AJC), the system of Hajdu, and the Surgical Staging System (SSS) were evaluated with respect to their ability to discriminate patients with different chances for survival in a series of 122 patients operated on with wide or radical surgical margins. None of the three systems could identify patient-groups with a significantly different prognosis better than that, that could simply be done by the histologic malignancy grading of the tumors. A multivariate analysis of variables thought to be of prognostic significance for local recurrence and survival was performed in a series of 144 patients with Grades III and IV soft tissue sarcomas. Marginal surgery, extracompartmental tumor location, and tumor necrosis increased the risk of local recurrence. Local recurrence, male sex, malignancy grade IV, tumor necrosis, and increasing tumor size increased the risk of tumor-related death.(ABSTRACT TRUNCATED AT 400 WORDS)

What is breast cancer doing before we can detect it?

Breast cancer is a cellular disease and the cellular kinetic events in the predetectable period are of great clinical significance. Such events include rate of replication, angiogenesis with distant metastasis, rate of cell death, and the number of cells needed to produce a detectable and later a symptomatic mass of neoplasm. A consideration of these events and their interrelatedness is reported using data from The Breast Cancer Detection and Demonstration Projects and significant reports in the literature. Growth rates in the predetectable period are estimated to be much faster than those that occur with grossly measurable breast cancers in keeping with the prediction of Gompertzian growth.

A simulation model of the natural history of human breast cancer

In order to assess the time at which the distant metastases were initiated, a model has been developed to simulate the natural history of human breast cancer. The metastasis appearance curves were fitted to those observed for tumours of various sizes among the 2648 patients treated at the Institut Gustave Roussy from 1954 to 1972. The model assumes that metastases are initiated when the tumour reaches a threshold volume (distribution of this volume was estimated in a previous article). Two patterns of growth were considered: exponential and Gompertzian. Distributions of tumour and metastases doubling times are fixed according to the literature. A relationship between tumour and metastasis doubling time is estimated. Simulations were used to optimize metastases growth duration as a function of the metastasis doubling time. The ages of the metastases at tumour diagnosis are calculated. With exponential growth, it was necessary to introduce correlations to obtain a satisfactory fit of the metastases appearance curves: between the tumour volume at diagnosis and the doubling time (R1 = -0.3), and between the tumour volume at metastasis initiation and the doubling time (R2 = 0.3). The growth duration of the metastases before their detection was found to equal about 18 metastases doubling times at detection and the mean ratio between the doubling time of a tumour and its metastases equal to 2.2. With Gompertzian growth, it was impossible to adjust satisfactorily the proportions of metastases at diagnosis as a function of the primary tumour volume. However, when we ignore this, the best fit was obtained when the duration of metastases growth before detection was about the same as for exponential growth. With either growth pattern, the model predicts that the proportion of patients with metastases would be reduced by approximately 30% if the primary tumours were treated 12 months earlier. This prediction is consistent with the results of the screening programs for breast cancer.

Growth rate of asymptomatic hepatocellular carcinoma and its clinical implications

The growth rate of 31 asymptomatic hepatocellular carcinomas (diameter less than or equal to 5 cm) discovered in 28 patients by a prospective screening program was determined by real-time ultrasonography over 36-860 days. Except for one tumor that shrank on follow-up, the doubling time ranged from 29 to 398 days, with a median of 117 days, an arithmetic mean of 136 days, and a geometric mean of 110 days. In 17 tumors with more than two measurements, the growth rate remained exponential in nine, declined in growth in seven, and showed an initial lag period in one. Doubling time correlated with initial tumor diameter but was independent of the patient's age, sex, hepatitis B surface antigen status, tumor location, liver function tests, stage of liver cirrhosis, histologic type, or grade of malignancy. Although initial alpha-fetoprotein levels did not correlate well with growth rate, in 14 patients with an exponential increase of serum alpha-fetoprotein, the alpha-fetoprotein doubling time was closely related to the tumor doubling time. Based on the above data, the median detectable subclinical period of hepatocellular carcinoma was deduced to be 3.2 yr, and the suitable screening interval for its early detection in our area was 4-5 mo.

Biochemical measure of the volume doubling time of human pulmonary neoplasms

The volume doubling time (DT) of human lung neoplasms, determined from sequential, presurgery roentgenograms, was compared with biochemical and histologic observations on biopsy samples of the same tumors obtained during surgery. The DTs of the 16 neoplasms ranged from 24 days in an oat cell carcinoma to over 500 in a pulmonary carcinoid tumor, and showed a statistically significant, inverse correlation to the TK (thymidine kinase) and the UK (uridine kinase) concentration of the biopsy samples per g wet weight or mg DNA. Log DT bore a linear relationship to log TK (r = 0.75, P = 0.0008) and to log UK (r = 0.69, P = 0.0067), and an even better fit to the straight line was found when plotting the log of the standardized average of the two enzymes against log DT. The results demonstrate the feasibility of a biochemical method for determining the unknown DT of the many tumors that are not amenable (on account of shape, location, or lack of prior chest x-rays) to the direct, radiologic determination of this useful, dynamic parameter of clinical malignancy.

Role of the CT scanner in the management of cancer

Although the diagnostic scope of computed tomography has widened considerably in recent years, assessment of patients with suspected or known malignant disease remains the major reason for body CT referrals in the United Kingdom. This paper sets out to define important advantages and limitations of CT in cancer diagnosis, addressing the topics of primary diagnosis, staging, and patient follow up. There is relatively little information on the influence of CT on patient management in oncology but reported studies indicate that CT directly alters clinical decisions in 14-30% of patients. This aspect requires further evaluation and is of particular relevance when considering the appropriate use of high cost technology.

Actual growth rate and tumour cell proliferation in human pulmonary neoplasms

Measurement of the Doubling Times [DT] for 27 human pulmonary neoplasms have been made. Squamous and large cell tumours had a wide range of values for DT whereas for small cell undifferentiated carcinoma, and possibly large cell undifferentiated carcinomata without stratification, the range was narrower. Mean DT for different primary bronchogenic carcinoma groups were: Squamous cell 146 days, Adenocarcinoma 72 days, Small cell 66 days, and Large Cell 111 days. The number of adenocarcinomata is very small in number and our value of 72 days is probably not representative of this group of tumours. Relationship between DT and tumour differentiation was difficult to identify in our series. Of these 27 a unique series of 17 have parallel data on DT and Potential Doubling Time (DTpot) and the Cell Loss Factor [0] calculated. Great discrepancy between DT and DTpot existed in each case and cell loss was high, ranging from 54% to 99%. All primary bronchogenic carcinomata had cell loss of greater than 70%; in almost two thirds of these cases the value was 90% or more. All undifferentiated tumours and a majority of poorly differentiated tumours had cell loss of 90% or more. As cell loss increased, tumour thymidine labelling index (TLI) increased and the tumours tended to be less well differentiated. The relationship, if any, between cell loss and DT was unclear.

Cell cycle parameters and prognosis of colorectal cancer

In vitro determination of S phase duration and labeling index were performed, in tumor and normal tissues, in 15 patients with rectal and colon cancer to determine if these cell cycle parameters can predict the clinical course of the disease. Microscopic analyses of the tumor and adequate follow-up were obtained for all patients. S phase duration and labeling index did not exhibit any obvious correlations with age, sex, tumor localization, Duke's classification or other microscopic prognostic features; neither did they show any difference between patients alive without cancer 5 yr after initial treatment and those dead from cancer or other causes.

Volume doubling measurement of spherical and ellipsoidal tumors

Volume doubling rulers are described for rapid estimation of tumor volume using projection areas of single-plane images such as chest radiographs. The potential utility of the rulers derives in part from the convenient relationships that exist for the interconversion of volume, volume doubling number, and decimal log growth or cell kill. The traditional approach to tumor volume doubling time determination, originated by Collins [1] uses the average diameter of approximately spherical tumors; analysis of the geometry of volume doubling shows this method to be nearly as accurate as methods that assume elliptical eccentricity, but only up to a tumor image length/width ratio of 1.5. For ratios greater than 1.5, it is shown that the clinical practice of taking perpendicular diameters is inherently more accurate. Where two perpendicular radiographic views of a tumor ellipsoid are available, it is shown that calculation of volume using the longest projection radius should result in less than one single volume doubling underestimate due to out-of-plane orientation of the long axis of the tumor. These methods should find greatest utility in measurement of multiple metachronous tumors that are well-circumscribed, convex in perimeter, and have low length/width ratios.

Choroidal melanoma growth patterns

Thirty patients with choroidal melanoma in whom tumour thickness was found to increase on serial examination were retrospectively studied. Often when tumours started to increase in thickness, after a period of relative quiescence, the growth rate was relatively rapid. Increased tumour thickness was associated with increased tumour growth. During the phase of active tumour growth the height of the lesion tended to increase more than exponentially. Possible inadvertent biases in the selection of the patients studied prohibit wide-ranging conclusions from these data.

L.H. Gray Medal lecture: cell kinetics and radiation oncology

Development of the study of human tumor cell kinetics during the past decades has deepened our understanding of the natural history of human cancers. Mathematical models based on the data which have been accumulated may help to evaluate, for the various types of human tumors, the time during their growth that the dissemination process occurred and to calculate the size distribution of the subclinical metastases at the time of treatment of the primary tumor. The perturbations caused by radiotherapy and chemotherapy are complex and include reassortment of surviving cells and repopulation. Currently it appears difficult in clinical practice to take advantage of cell reassortment while the differences in the rate and in the duration of repopulation between normal and neoplastic tissues are exploited in most therapeutic regimens. A better knowledge of cell and tissue kinetics following treatment may help to optimize the treatment scheduling in particular during combined administration of radiotherapy and chemotherapy. The study of the kinetics of proliferation in normal tissue has shown the existence of several types of inhibitory and stimulatory humoral factors. These, when purified, can be used to manipulate the proliferation of critical normal tissues in order to protect them during the administration of cell cycle specific drug or to accelerate their regeneration after treatment.

The growth rate of bone sarcomas and survival after radiotherapy with tourniquet-induced hypoxia: a clinical study

The volume doubling time of primary bone sarcomas and lung metastases was determined by measurements made on serial radiographs. For the primary tumors, the volume doubling times were log-normally distributed and varied in the range of 20--200 days with a mean around 50 days. The volume doubling times of the metastases also showed a log-normal distribution in the range of 10--100 days, but with a mean twice as short as that of the primates. Radiation therapy was given with three--four doses of 20--25 Gy to the tumors that, together with the surrounding normal tissues, had been made hypoxic by the application of a tourniquet. Amputations were not performed unless required eventually by some serious late radiation damage, such as grave functional deficiency, and/or painful fibrosis and ankyloses. In no case did microscopic examination of the amputated tissues reveal the persistence of any viable, neoplastic cells. The five-year survival of a total of 69 patients was 26%. Survival expectancy was found to be closely related to the volume doubling time of the tumors, as was the incidence of the metastases. The data stress the importance of volume doubling time as a predictive factor and indicate, furthermore, that treatment with a few massive radiation doses in combination with tourniquet-induced hypoxia is effective in the local control of bone sarcomas. The several late reaction of the normal tissues to the treatment will, however, require amputations in most of the five-year survivors.

Uveal melanoma: location, size, cell type, and enucleation as risk factors in metastasis

In this series of 3,432 cases of malignant melanoma of the choroid and ciliary body, mortality from metastasis 15 years after enucleation was 46 per cent. This mortality was at least ten times greater than has been observed with tumors of the iris, probably owing to the greater size and more malignant cytology of choroidal and ciliary body tumors. In 56 per cent of the 3,432 cases, the melanomas were composed of a mixture of spindle and epithelioid cells. The 15-year mortality of patients with melanomas of mixed cell type was three times that of patients with tumors of pure spindle cell type. In 30 per cent of the cases in this series, the melanomas of the choroid and ciliary body were larger than 15 mm in diameter. Size was highly correlated with mortality. The distribution of deaths following enucleation in the 3,432 cases was a log-normal function of time from enucleation. This indicated that metastasis occurred in these fatal cases close to the time of enucleation. The authors were also able to infer that many years were usually required for these uveal melanomas to grow from small (7 to 10 mm in diameter) to large (greater than 15 mm in diameter). These observations are consistent with the hypothesis that dissemination of tumor cells at the time of enucleation has been a major cause of metastasis with small and medium-sized uveal melanomas.

Enzyme pathology and the histologic categorization of human lung tumors: the continuum of quantitative biochemical indices of neoplasticity

The purpose of the present enzymic and histologic analysis of pulmonary samples from 39 subjects was to discern a common, meaningful pattern which may underlie the biochemical heterogeneity of lung neoplasms. The distribution among the different tumors of thymidine kinase, uridine kinase, phosphoserine phosphatase, hexokinase and adenylate kinase was found to correlate with each other. By averaging their standardized units (normal lung = 0) an enzymic index of neoplasticity was calculated for each tumor and used (in increasing order) to rank all 39. The index, showing a significant positive correlation with mitotic frequency, encompassed a continuous 100-fold range. Poorly differentiated carcinomas ranked high while neoplasms with better differentiation and prognosis placed in the lower half of the range. The results indicate that enzymes showing coordinated variations over a broad spectrum of tumors could contribute objective criteria to the rating of any individual tumor against a continuous, quantitative scale of neoplasticity.

Association between the actual doubling times of primary breast cancer with histopathologic characteristics and Wolfe's parenchymal mammographic patterns

This study identifies associations between the actual doubling time of primary mammary cancers with histopathologic characteristics and Wolfe's parenchymal mammographic patterns. Seventy microscopic criteria and Wolfe's mammographic parenchymal patterns were coded for 32 primary breast cancers on which actual volume doubling times were calculated from serial mammographic views of tumor nucleus shadows. Circumscribed cancer margin and papillary intraductal growth were associated with slow-growing breast cancers. More anaplastic nuclear grade was associated with faster-growing cancers. No association could be established between doubling time and parenchymal patterns as described by Wolfe.

The primary and secondary prevention of cancer

Prevention of cancer is now divided into primary and secondary prevention. Primary prevention is that set of interventions that keeps a cancerous process from ever developing and includes health counseling and education, environmental controls. and product safety as examples. Secondary prevention is that set of interventions leading to the discovery and control of cancerous or precancerous processes while localized, i.e., screening, early detection, and effective treatment. Risk is lifelong for all, though it may vary in intensity among different groups. Jointly, primary and secondary prevention must be synthesized into optimum life time strategies that are best understood and evaluated under certain basic concepts of the epidemiology of cancer and operations research. The purpose of this report is to provide a brief review of these concepts applied to primary and secondary prevention of human cancer. Improved understanding of these concepts is essential for planning, implementation, and evaluation of prevention programs.

Are growth rates of tumors of any clinical importance?

The tumor doubling times were determined in 142 rounded pulmonary lesions of 78 patients (13 bronchial carcinomas, 7 benign pulmonary tumors, and 122 pulmonary metastases). They varied between +12 and +8863 days of tumor growth and of -1810 days of decrease in tumor mass. Forty-four percent of all pulmonary metastases doubled their volume within 60 to 250 days. The growth rates during the period of observation varied greatly in several pulmonary metastases of the same patient, even for the same solitary circular lung focus of the same person. There is no relationship between tumor doubling time and histological type of the tumor, nor between the interval between operative removal of the primary tumor and the occurrence of pulmonary metastases. In patients between the ages of 10 and 30 years only rapidly growing pulmonary metastases with a tumor doubling time of less than 60 days could be found; even though there is no proved relationship between growth rate and age. The tumor doubling time gives no useful information on the nature of a circular lung focus, and there are no clinical consequences for diagnosis.

Diagnostic techniques: their strengths and weaknesses

The diagnostic techniques available for estimating tumour volume in patients are reviewed, using tumours in the lungs and lymph nodes to illustrate the advantages and disadvantages. Tumour growth in lymph nodes is very difficult to assess using lymphography but useful information has been obtained in highly selected patients. The introduction of ultrasound and CT have provided a method of assessing tumour size once it has broken out beyond the confines of the node. In general, CT appears to be the most accurate method of estimating tumour regression and growth of abdominal tumour at the present time. Physical imaging techniques have been used in various other sites for estimating tumour volume but the main advantages and disadvantages of conventional radiology, ultrasound and CT have been illustrated. Isotope scanning and thermography have not been widely used to quantify tumour volume because other techniques provide better delineation of the tumour margin which is the most important factor. However, even the most accurate methods available today are still dependent on subjective visual assessment.

Growth rates of primary breast cancers

The growth rates of breast cancers are a critical aspect of the natural history of the disease. Growth rates of 32 primary breast cancers were determined from serial mammographic views of tumor nucleus shadows in a population of 109 cancers. These cancers were found in a screening population of 10,120 women receiving over 30,000 mammograms over 3 years. Tumor volume doubling times ranged from 109 days to 944 days with mean doubling time of 325 days in 23 cases with 9 tumors showing no growth. Additional cancers surfaced that were growing too fast to be measured. These cancers were significantly more likely to metastasize but because of the small sample size the absolute percentage of tumors in that fast growing subset was not determinable but ranged between 17 and 77% of the 109 cancers.

Relation between mammary cancer growth kinetics and the intervals between screenings

The purpose of this study was to consider the time interval for periodic mammographic screening for breast cancer. One hundred fifteen breast cancers occurring in 10,128 women receiving over 30,000 mammograms over a four year period were reviewed. Tumors were diagnosed at three time intervals: 1) first screening (39/115); 2) annual examination (27/115); and 3) at an examination that occurred less than twelve months from a previous annual examination (10/115). Also, there were tumors that grew to a palpable dimensions and were self-detected between annual examinations (39/115). Our opinion is that screening intervals should be individualized to each patient according to risk factors and suspicious mammographic findings. Further, there is a significant number of breast cancers that grow too fast to be detected effectively by annual mammography. Suspicious mammographic findings did not exist before these cancers reached palpable dimensions. Other risk factors characterizing the hosts who develop these fast growing cancers are yet to be determined.

Current management of melanoma

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