# PHOTO THERAPY OF BLADDER CANCER WITH HEMATOPORPHYRINS

> **NIH NIH R01** · MASSACHUSETTS GENERAL HOSPITAL · 1987 · $240,856

## Abstract

Porphyrin-sensitized photoradiation therapy (PSPT) is a promising treatment
modality for a variety of malignant tumors, and is currently a subject of
active research and development in many institutes.  The overall goal of
our project is to develop PSPT for bladder carcinoma.  We have made
substantial progress during the past funding period, both in basic studies
and in the development of this treatment.  The current application will
enable us to continue our efforts in achieving this goal.

In this application, we intend to concentrate our clinical studies on the
development of "whole bladder wall photoradiation" to treat superficial
tumors including carcinoma-in-situ (CIS), after sensitizing the tumor with
hermatoporphyrin derivative (HpD).  The photoradiation will be accomplished
by a 514 nm laser light delivered through an optical fiber with a
dispersion tip, which when situated at the center of the bladder will
distribute the light to illuminate the entire bladder wall.  Basic studies
will be carried out to elucidate some of the mechanisms of PSPT as a basis
for improving the treatment.  These will be centered around the theory that
molecular aggression and deaggregation play major parts in porphyrin
uptake, retention and photosensitization, and the "non-exchangeable"
porphyrin (NEP) may be an "in vivo active component" of HpD.  Studies will
be carried out to investigate the porphyrin composition and the physical
state of NEP, the relationship between active HpD component and the
formation of NEP, and the possible association of NEP with subcellular
sites.  Also to be studied are the interactions of plasma and cellular
proteins with the porphyrins; the effect of protein binding on porphyrin
uptake, retention and formation of NEP, and intracellular proteins
associated with NEP.  Several pre-clinical studies will also be carried out
to explore new approaches of PSPT.  These include combination with
hyperthermia, use of other types of lasers and light at wavelengths other
than nm.

This project offers the potential for a new modality in treating recurrent
and resistant bladder cancer, some of these cannot be treated
satisfactorily at the present.  Information gained form the basic studies
will provide a better understanding for mechanisms of porphyrin uptake,
retention and photosensitization in tumor cells, thus providing a basis for
improving the treatment by increasing the efficacy and reducing the side
effects.  The development and the information can also be useful in the
treatment of other tumors by PSPT.

## Key facts

- **NIH application ID:** 3170243
- **Project number:** 5R01CA032259-05
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **SAM.gov UEI:** FLJ7DQKLL226
- **Principal Investigator:** GEORGE R. PROUT
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $240,856
- **Award type:** 5
- **Project period:** 1982-04-01 → 1989-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3170243

## Citation

> US National Institutes of Health, RePORTER application 3170243, PHOTO THERAPY OF BLADDER CANCER WITH HEMATOPORPHYRINS (5R01CA032259-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3170243. Licensed CC0.

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