SGR acceleration SGR after Rx SGR before Rx t211 A positive number

The dynamic of PSA change was used as an early predictor of overall survival after a short exposure to docetaxel therapy (4 doses). Knowledge that a drug may extend survival after just a short exposure would minimize toxicity from ineffective drugs. Hannenin's work [81] found that a rapid rate of PSA decline expressed as PSA half-life <70 days was associated with a longer overall-survival Figure 13. This result was independent of other known markers of survival and allowed for a greater survival differentiation than PSA suppression alone. Response-time evaluations may play a new role in determining drug efficacy earlier than usual. I would propose study of an alternate expression for tumor acceleration or deceleration in terms of SGR as: SGR (accel...decal) = SGR2-SGR1/(t2-t1). The value of this expression may be positive for acceleration or negative for deceleration.

De Crevoisier [82] found that a PSA decline 6 weeks after the start of EBRT when used as monotherapy and 3 months after the start of androgen deprivation therapy (ADT) in patients treated with combined ADT and external beam radiation is predictive of progression and specific survival.

Figure 13. Treatment-associated tumor/marker deceleration in response to docetaxel. The magnitude of rate of change (acceleration-deceleration) of SGR resulting from therapy is an early predictor of prostate-specific survival.

Figure 14 illustrates a computer analysis of a prostate cancer patient treated with docetaxel. A pelvic node is noted to grow over 4.5 months from 1.3 to 1.6 cm in greatest dimension. This establishes the pre-therapy SGR of 0.46%/d and the tumor volume (assuming a sphere) before starting therapy is 2.1 cc. Fifty-one days of therapy induces a decrease of tumor diameter to 0.9 cc and a decrease of tumor volume to 0.38 cc. Had the tumor grown uninterrupted the project ed tumor volume would have been 2.7 cc. In this case, the value for deceleration of SGR for the tumor: is given as (SGR2 after Rx - SGR1 before Rx) / (t2-11) = -0.021% / d / d.

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1 1

Cancer Pal Tumor Kinet¡cs Analysis

Dato cm or marker unit



TSGR1 of vol ■ 0.46 %/d TSGR2 - -0 60 %/d

TVDT= 149.11 (1= 4.97 m TVDT2 = -116.24 d = -3.87 m

TDx vol: 1.150 cc TPreRx vol: 2.145 cc TPostRx vol: 0.382 cc

Projected vol it untreated 2.71B cc

TPte-TPosifu 51 a = 1.7 in TSGRaci =-o.C2tie "rt/6ia Treatment Response 2.0 TumorAge -12.30 years

^^^^ @ 0

Figure 14. This calculation displays results for a patient treated with docetaxel (see text).

Figure 14. This calculation displays results for a patient treated with docetaxel (see text).

This is an objective measure of the rate of change of SGR. The treatment response is displayed as = + 2.0. This assigns a calculated continuous variable as a measure of the degree of response and is used to objectively compare docetaxel efficacy to any other administered drug. Positive TR values represent tumor reduction compared to the projected tumor size while a negative TR represents tumor growth relative to the projected size. Estimated age of tumor, here approximated ~ 12.3 years, is a calculated value based on the initial SGR of 0.46%/d in the absence of therapy. This assumes constant, continuous exponential growth over many years. Tumor age calculations are gross approximations and notoriously subject to large error.

Figure 15 illustrates the evaluation for a 68 year-old man undergoing watchful waiting for a Gleason score 3+3 = 6, T1c prostate cancer. Three PSA values are displayed for three sequential dates. When the patient was asked if he had changed medication between 3/2/11 and 5/1/11 he noted he was ingesting a new Chinese herbal mixture sold to enhance energy and libido.

Ttimor Kinetics Analysts


Ttimor Kinetics Analysts cm qt rmrtaer unit

MSGR1 = 0.07 Vd MSGR2 a 0.13 NIDT1 =923.4(t= 30.9m MDT2 = 517 = 17 3 m

Pmjectcd Marker untrtarart a 5.98 units

Marker Response = -0.05

Figure 15. Evaluation of a 68 year-old man undergoing watchful waiting for a Gleason score 3+3 cancer. The patient was ingesting a stimulatory Chinese herb.

= 6, T1c prostate

Subtle acceleration of the tumor marker value was uncovered by inspection of the projected PSA value for 5/1/11 as compared to the actual measured value for that date. Notice the confirmative quantitative measures given by the calculation Figure 14 of the marker specific growth rate MSGR2 = 0.13%/d compared to MSGRj = 0.07 %/d; marker doubling time MDT2 = 17.3 months compared to the initial MDTj = 30.9 months; by both the positive value for MSGR acceleration = +0.001%/d/d and by the negative value for marker response MR = -0.05. Based on the marker-specific growth rate (MSGR) for the first interval TDx thru TPRx (the date at initiation of therapy) of 0.07%/d, the App calculated the expected PSA on 5/1/11 to be 5.98 ng/ml. However, the measured value was higher = 6.3 ng/ml. The negative value for MR of -0.05 indicates a negative marker response thus PSA expansion (marker acceleration confirmed this = +0.001%/d/d). We suspected that the Chinese herb might have caused subtle acceleration of PSA production and or tumor growth. Other explanations for acceleration of the PSA value include decreased clearance of PSA or the subtle appearance of a mutated, faster growing clone of PSA-producing tumor cells. Note that in the absence of knowledge of the inherent initial PSA-SGR between 2/1/11 and 3/2/11 and calculation of the expected projected value of PSA for 5/1/11, the subtle PSA acceleration would have been missed.

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