The relative independence in the loss of the defense capacity of different entities would explain one of the most baffling problems of cancer—why certain cancers tend to metastasize to certain organs or tissues. Some cancers show bone metastases, others spread to many organs, while still others spread only to certain specific organs. This can be explained by a loss of the defense capacity at the organ level. While some organs lose, others still maintain their allergic defense capacity. The circulating cancer cells will induce multiple metastases in the first but will not be able to take hold in the latter.

A similar mechanism can also explain the persistence of inactive cancer cells for years after an operation. The defense mechanism, while it is not able to affect the cells and destroy them, is still sufficiently active at the tissular level to prevent the condition from progressing at this level. The cancer cells will start to invade this level only when the tissular level is unable to defend itself further through an allergic response against the invading cells. By losing its allergic response capacity, the tissular level will even exaggerate the corresponding lower primary stage of defense, that is, the prolonged lipidic phase with the consequent changes which this brings on. Among them would be the appearance of pain.

Under these circumstances, the general immunological condition favorable to the hierarchically progressive development of cancer has to be regarded as the loss of the capacity of the different levels for an effective allergic response toward cancerous entities. The immunological problem of cancer consequently appears in a special light, different from all the other known conditions where an unsuccessful immunological response is present. In the other conditions, the problem of the inability to conquer an antigen is one involving the incapacity to mobilize or develop an effective immunological response. In cancer, the body appears to have lost a previously existing capacity that was present before the disease appeared. In other diseases, the immunological problem is to create a new and favorable condition in the fight against an antigen, by developing means which do not exist in the normal individual. In cancer, the immunological problem would be to prevent the loss of a property possessed by normal subjects or. if already lost, to find some means to regain it.

These considerations and the study of the different factors involved in the development of the progressive defense stage has led us again to the role of the lipids in these processes. The appearance of a stage in the defense mechanism seems to be strongly related to the fulfillment of the qualitative requirement for the previous stage. Deficiency of essential factors in one stage represents an impediment for the next stage. In the case of cancer, failure of the specific allergic phase thus could be traced to a qualitatively inadequate preceding lipidic phase. A level is unable to surmount an allergic defense because the lipids which can mobilize are qualitatively inadequate. Even abnormal richness in lipids thus could be interpreted as resulting from their qualitative inadequacy. This very excess indicates their importance.