Small Tumors

Most breast cancers diagnosed are small tumors (less than or equal to 2 cm), and disease is localized in all racial and ethnic groups. However, blacks and other minority women have proportionally more cases of disease diagnosed at more advanced stages compared with white women. This is thought to reflect access to and use of screening mammography and timely treatment. 

Gamma knife A device that uses multiple converging beams of gamma radiation from cobalt-60 to highly focus radiation on small tumors within the brain. 

In women with lower-genital-tract carcinomas—cervical, vaginal, and vulvar carcinomas—hematogenous metastases are rarely present at diagnosis, and thus disease can frequently be controlled with local treatment. Small tumors can usually be treated with surgery alone, but cancers that penetrate deeply, particularly those that involve adjacent... 

Power Doppler sonography displays the amplitude of the Doppler signal but lacks the velocity and directional information present in frequency-based color Doppler sonography (10). However, power Doppler is more sensitive in the depiction of tumor vascularity (14-16), specifically within small tumor vessels (10,17). The hind limb tumor model and power Doppler can be utilized to measure the response of tumor blood vessels to radiation, providing longitudinal assessment of microvascular response within the same tumor without the need to section tumors for histology at various time intervals. 

This study shows that assessment of ERCC 1 mRNA expression in patient tumor tissue is feasible in the clinical setting and predicts response to docetaxel plus cisplatin. Further studies are warranted to optimize methodologies for ERCCI analysis in small tumor samples and to refine a multi-biomarker profile predictive of patient outcome. Other... 

The idea. In 1961, Judah Folkman, a young surgeon, noted that cancer cells injected into isolated in vitro thyroid preparations grew to small tumors and then stopped growing. However, the same cancer cells grew into massive tumors when implanted into mice. Folkman realized that the in vivo tumors had something the in vitro system did not have—a rich vascular bed and blood supply. 

Another advantage of immunohistochemistry is that tissues of a small size (e.g., biopsies) can be used. This is important because it is better to detect tumors at an early stage, when they are small. The necessity of early detection cannot be overemphasized. Very small tumors and fine-needle aspirates cannot be used for biochemical assays. Although the DCC assay provides quantitative results, it does not take into account the relative amount of the connective tissue in the specimen, the presence of carcinoma in situ lesions, or normal ducts and lobules. These limitations are not encountered when using paraffin sections. In addition, immunohistochemistry allows the use of archival tissues when fresh tissues are not available. This method does not require any special, expensive equipment and can be carried out in any standard laboratory. 

The second involvement of the immune system occurred when we were able to cure large solid Sarcoma-180 tumors in ICR mice. The cured animals rejected any new attempt to reimplant this tumor up to 11 months later. They have obviously developed a heightened immunologic reactivity for this tumor. Interestingly enough, the cure of small tumors did not produce such an immunologic rejection reaction. 

First, transformation events have to occur, changing a normal cell into a tumor cell, which has to grow progressively to form a small tumor mass, initially supported by simple diffusion of nutrients. 

It was recently observed (K2) that a kidney with a small tumor excretes more of the so-called carcinogenic o-aminophenols (3-hydroxykynurenine and 3-hydroxyanthranilic acid) than the opposite healthy kidney after a 100 mg/kg loading dose of L-tryptophan. The small size of the hypernephroma encountered at nephrectomy and also the higher excretion of carcinogenic metabolites of tryptophan previously thought to be restricted to tumors of transitional-cell epithelium (K2) are emphasized. 

Except in the pregnant patient, AFP levels greater than 1000 pg/L are indicative of cancer. At these levels of AFP, about half of hepatocellular carcinomas may be detected. However, because the serum level of AFP correlates with the size of the tumor, detection of hepatocellular carcinoma is more useful at the earlier stages, when the tumor is small enough to be resectable (less than 5 cm) than when the tumor is large. To detect small tumors, the cut-off level for AFP has to be set at a low level a cut-off point of 10 to 20pg/L has been recommended. However, at this level, hepatitis and cirrhosis must be considered as possible causes of elevation. 

Diagnosis of a TSH-secreting adenoma should be made by demonstrating lack of TSH response to TRH stimulation, elevated a-subunit levels, and radiologic imaging. Note that some small tumors are not identified by MRI. Moreover, 10% of normal individuals may have pituitary tumors noted on pituitary imaging. ... 

Fig. 3. Integral dose ratios for whole antibody (IgG) and a small tumor-binding ligand at increasing affinities (Keq).

Fig. 4. Effect of injected dose on (top) peak tumor normal tissue UR for whole antibody (IgG) and a small tumor-binding ligand, and (bottom) peak tumor content as a percentage of injected dose for all molecular sizes. Affinity in all cases (Keq) = 1010/M. Arrows show the typical doses used in antibody scanning.

Although the architecture of tumor blood vessels has been studied using a number of techniques, one of the most fascinating involves the use of acrylic resin casts. This is exemplified by the work of Skinner et al (1), who studied a series of chemically induced tumors in rats. A resin solution was injected intraarterially into the anesthetized rat, the animal was killed, and the blood vessels to the tissue, were clamped while the resin set. Tissue was digested with alkali and the cast coated with gold and examined by electron microscopy. Whereas normal colon mucosa showed a consistent regular pattern, tissue from tumors showed considerable disorganization with marked dilation and tortuosity of capillaries. For small tumors it was possible to discern areas in the tumor that... 

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