Cancer Misdiagnosis & Delayed Diagnosis

Understanding the Tumor Doubling Defense

The growth of a tumor mass inevitably results in the mass doubling in size over time. Experts defending delay in diagnosis of cancer cases have used this seemingly innocent and logically necessary, though irrelevant, observation over the last twenty years to lead juries to ignore common sense and find that the negligent failure to have earlier diagnosed cancer was meaningless because the death or morbidity was inevitable. It is the object of this article to examine this defense and demonstrate its fallibilities.

A primary tumor starts from a single cell. This first tumor cell multiplies geometrically over time. Assuming the cell and its progeny survive, the number of cells present increases by a factor of two, between generation from 1 to 2-4-8-16-32, and so forth.

In fact, the increase in the number of cells present in a given tumor depends on the percentage of cells proliferating, the cell cycle time of those cells that do proliferate and the fraction of tumor cells that do not survive. The net growth of the tumor volume will remain reasonably exponential only if one presumes that these factors remain constant.1 This presumption is demonstrably false with respect to metastases and at different parts of the growth cycle.

In virtually every trial where the tumor doubling time defense is raised, an exhibit in the form depicted in figure 1 is presented:

Such an exhibit hopes to persuade jurors to think of a very small tumor of, for example, .2 cm. to 1 cm. in diameter as having great malignant potential far out of proportion to its size. For example, a 1 cm. tumor contains 109 (1 billion) cells. Figure 1 presupposes that the tumor cells having a diameter of 10 µm require 32 cell divisions to acquire a 1 cubic cm. mass containing 109 cells. Note, that if one assumes the tumor cells are 25 µm in diameter, 26 doublings would be required to reach the same volume but would contain 1/64th as many cells or about 15,000,000 as opposed to 1,000,000,000.

Of course, the difference between 15,000,000 and 1,000,000,000 cells is not particularly relevant unless the number of cells present impacts upon the clinical treatment of the cancer and its prognosis, if earlier treated. As early as 1981, Spratt, a leading proponent of the tumor-doubling defense, urged that cancer therapy could make no difference once a tumor has reached 9 doublings.2 That is, Spratt would have a jury believe a tumor containing 512 cells had metastasized with unavoidable fatal consequences.

Whether one assumes that a cancer cell is 10 µm or 25 µm in diameter, it is easy to see that even at 14 doublings (a more generous number suggested by Spratt), breast cancer would be invisible to mammography. If Spratt's analysis were correct, by the time a cancer diagnosis can be made, effective treatment can no longer be provided. However, no one, including Spratt, has proven in general or in any specific case that the metastasis that kills the patient occurred before 14 doublings or that even if metastasis had occurred, that early treatment would not have been helpful. Cancers, if untreated, eventually kill, either because they interfere with organ function or because cancer tissue competes with normal tissues for nutrients. Eventually, because cancer cells proliferate indefinitely, their number daily multiplying, cancer cells will demand a critical portion of nutrients available to the body as a whole. This critical amount is known as lethal tumor burden. The lethal burden in most patients is reached at 1012 to 1013 cells, a tumor volume containing between 1,000 and 10,000 times the number of cells present after 32 doublings. Often the argument is made that, at 32 doublings (a time when a tumor may weigh as little as 1 gram and is pea-sized), the tumor is nearing its biological end. Plaintiffs' lawyers should remember, however, that during the short remaining life of that same tumor, it would undergo a 1,000 to 10,000-fold enlargement. It takes two-thirds of its life to reach 1/1000th to 1/10,000th of its lethal volume.

Put more simply, a tumor takes two-thirds of its life to go from something much smaller than a grain of sand to something slightly larger than a pea. Yet, the jury is urged to believe that the metastatic potential of this pea must be great because it contains 1,000,000,000 cells. This deception is facilitated by showing that the further growth of the tumor to its lethal volume occurs in a short period of time. Figure one is an example of an illustration seen at trial. The size of the tumor and number of cells required to reach its lethal burden is not depicted. In fact, a mass representative of lethal tumor volume should be just under 5 inches in diameter and contain 1012 cells. The pea-sized mass is in fact a trivial part of the ultimate growth of the tumor to its lethal potential containing 1000 times as many cells. A juror, given the opportunity, is not likely to believe a grain of sand has the malignant potential of a golf ball-sized mass containing 10,000 times as many cells. Proponents of the tumor-doubling defense succeed if they can avoid such common sense comparisons.

The assertion that fatal metastasis has always occurred before the tumor can be detected is sheer speculation and is readily disproven by the remarkable cure rates for diseases such as cervical cancer, which remains eminently curable even after invasive cancer has developed.

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